President Trump’s campaign is seeking to weaponize this case against the Democrats’ presumptive nominee. But it’s also a complicated allegation. Let’s break down what we know about it.

1993: Former vice president Joe Biden was then a powerful senator, having been in the Senate for 20 years. At the time, he was chairman of the Senate Judiciary Committee. Tara Reade, 28, joined the office in late 1992 in an entry-level staff position. One of her duties was managing interns.

Spring 2019: Biden prepares to run for president, and about half a dozen women share stories of unwanted touching by Biden that they said made them feel uncomfortable. Biden said his intention was to offer affection and comfort as a politician but recognized that times had changed and promised to be more respectful. He did not apologize and joked about the criticisms a few days later.

Reade was one of those women, saying that at least three times, Biden put his hands on her shoulders and the base of her neck. She also said she was asked to serve drinks at a reception and overheard a colleague suggest it was because she was pretty and Biden liked her legs. She told The Post she complained to supervisors and was asked to look for another job. In an interview with The Post at the time, she does not mention sexual assault, and she gives varying reasons for her departure from his office at other times.

Early 2020: Voting in the Democratic presidential primaries gets underway, and Reade is a vocal supporter of Sen. Bernie Sanders (I-Vt.), although she told The Post that politics didn’t factor into her decision to make the allegation.

March: Biden shores up the Democratic nomination, and Reade gives an interview in a podcast in which she makes the sexual assault allegation. She said she was delivering Biden a gym bag somewhere in the Capitol area (which has multiple buildings) but doesn’t remember exactly where. She said Biden pinned her against a wall, reached under her skirt (she said she wasn’t wearing any stockings) and pushed his fingers inside her. From her interview in April:

“He put me up against the wall and took the bag,” she said. “He reached up underneath my skirt … I remember two fingers … It was such a nightmare.”

She said he asked, “Do you want to go somewhere else?” She said that when she pulled away, he said, “Come on, man, I thought you liked me,” then told her that she meant “nothing” before finally grabbing her shoulders and saying, “You’re okay.

Biden’s campaign denies this ever happened.

April 12: The Post and the New York Times both publish investigative reports on the same day. Both reports find a friend who anonymously corroborates Reade’s story, but they also find half a dozen to a dozen former staffers at the time who do not recall something like this or any other assault allegation taking place.

April 24: A 1993 clip of a Larry King CNN show surfaces. A woman who called in to the show that year, identified as from the city where Reade’s mother would have been living at the time, said her daughter was having “problems” with “a prominent senator” and wanted suggestions other than going to the press. She did not mention any names nor give details. Reade has since heard the recording and said it was her mom, who died in 2016.

April 27: Business Insider reports that Reade’s neighbor in the mid-1990s said that Reade told her Biden had “put his hand up her skirt and he put his fingers inside her,” which is what Reade accuses Biden of doing. This neighbor was willing to go on the record with her name. “I remember talking about it,” Lynda LaCasse told Business Insider. LaCasse lived next to Reade in California in 1995-1996, where Reade moved after working in Washington. She confirmed her comments in a text message to The Post, saying she is “a very strong Democrat and am supporting Joe Biden during this election.”

Reade told The Post that after it happened, she told her mother, her brother and a friend but did not mention a neighbor.

Reade went on to work for a California state senator, and Business Insider talked to a former staffer at the time, Lorraine Sanchez, who said Reade told her that a former boss in Washington, D.C., had sexually harassed her and that she had been fired after raising concerns. Sanchez did not recall whether Reade specifically mentioned Biden. Sanchez did not respond to messages from The Post.

May 1: In a statement and an interview with MSNBC’s Mika Brzezinski, Biden denies the accusation and urges the Senate to look up his records for any complaint Reade may have filed against him.

May 7: Reade responds in an interview with former Fox News and NBC anchor Megyn Kelly. “You I were there, Joe Biden,” she said when asked what she would say to him. “Please step forward and be held accountable. You should not be running on character for the president of the United States.” She says she would go under oath and that she would take a polygraph test if Biden took one.

Biden issued his statement minutes before he addressed the allegation publicly Friday on MSNBC’s “Morning Joe,” saying: “It’s not true. I’m saying unequivocally it never, never happened, and it didn’t. It never happened.”

He also said that no one on his staff raised such a complaint to him.

Biden said if Reade filed a personnel complaint at the time, it would be in the National Archives, and he urged the National Archives to search for any such complaint.

“I’m confident there’s nothing. No one ever brought it to the attention of me 27 years ago, any assertion at all. No one that I’m aware of in my Senate office at the time is aware of any such request or any such complaint,” he said. He added:“This is an open book. There is nothing for me to hide at all.”

Sexual assault allegations are almost always difficult to assess for credibility. Because the act in this allegation took place decades ago, and because Reade initially came out with a different story about what happened, this one is also complicated.

Last year, Reade said Biden’s touching of her neck and shoulders made her feel uncomfortable. But she did not make any mention of sexual assault, which is far more serious. In fact, she appeared to defend Biden: “This is what I want to emphasize: It’s not him. It’s the people around him who keep covering for him,” she told The Post at the time. She added: “For instance, he should have known what was happening to me.… Looking back now, that’s my criticism. Maybe he could have been a little more in touch with his own staff.”

A few people have corroborated parts of Reade’s accounts. Her former neighbor in California went on the record this week confirming Reade’s story, saying she is sure she heard about it a few years after Reade alleges the assault occurred. Reade told The Post that she told her mother (who died), her brother (who initially told The Post he heard a different story that did not involve sexual assault and days later texted to say he remembered hearing Biden put his hand “under her clothes”), and a friend (who anonymously corroborated hearing her assault story).

Reade said she complained to three supervisors at the time in the Biden office. All three said they don’t remember any complaints from her. One, Biden’s executive assistant at the time, Marianne Baker, put out a statement via the Biden campaign specifically denying Reade’s allegation:

In all my years working for Senator Biden, I never once witnessed, or heard of, or received, any reports of inappropriate conduct, period — not from Ms. Reade, not from anyone. I have absolutely no knowledge or memory of Ms. Reade’s accounting of events, which would have left a searing impression on me as a woman professional, and as a manager.

Reade also says there is a paper trail, but journalists have been unable to locate a central piece of that. She said she filed a complaint with a congressional human resources office about her treatment in Biden’s office — but not about the assault allegation — in 1993. She said she does not have a copy of the complaint, and The Post could find no record of it. The office she probably would have filed a complaint with has since morphed into a different office.

It’s possible that corroborating evidence of the complaint could be found in Biden’s archive at the University of Delaware, but the university said these papers will be sealed until two years after Biden retires from public life — unless he were willing to release them.

Biden said the papers at the University of Delaware actually contain his public speeches and papers and transcripts of private conversations with world leaders, not personnel documents related to the management of his Senate office. Biden said personnel records would be at the National Archives, which houses old Senate papers, and called on them to release any record of Reade’s complaint. He wrote a letter urging the Secretary of the Senate to take “whatever steps necessary” to search his records, but on Monday, the secretary said the law prohibits releasing such records.

When pressed on MSNBC to do a search at the University of Delaware for Reade’s name, Biden maintained that all personnel issues are at the National Archives and worried that the release of his records relating to being in public office could be taken out of context in his presidential campaign.

Reade said she filed a police report this April after talking to The Post and Times about the alleged incident because she was being harassed online about it. The report repeats what Reade has said publicly: “Subject-1 disclosed that she was the victim of a sexual assault which was committed by Subject-2 in 1993.” D.C. police say the investigation is inactive. Filing a false police report is a crime.

Reade told The Post she told a therapist earlier this year about what she says happened. The Post asked Reade for the therapist’s notes of that conversation, but she has not produced them.

Reade did not mention her divorce records as potentially containing corroboration, but in May, the Tribune in San Louis Obispo, Calif., found a 1996 court document in which her now ex-husband described her state of mind. It said: “On several occasions, [she] related a problem that she was having at work regarding sexual harassment, in U.S. Sen. Joe Biden’s office.” The document does not mention Biden specifically as the harasser nor mention sexual assault. It does say Reade “told me she eventually struck a deal with the chief of staff of the Senator’s office and left her position.” The chief of staff at that time, Ted Kaufman, said in a statement that never happened.

Beyond the paper trail and corroboration, another thing that would bolster the accusation is if there is evidence of a repeated pattern of sexual misconduct by the accused. Extensive investigations by some of the nation’s best journalists have thus far found no other accusers of Biden but did turn up denials by staffers who worked for him at the time that something like this could happen. By contrast, more than a dozen women have accused Trump of sexual assault or groping, and he is on tape bragging about such behavior.

Biden is the leading figure of a party that has striven to present itself as the antithesis to Trump, including — perhaps especially — when it comes to Trump’s behavior. As such, Democratic Party leaders have tried to position themselves as having a zero-tolerance policy toward sexual misconduct. Democratic senators pushed out Sen. Al Franken (D-Minn.) in 2018 after he faced multiple accusations, which he denied. Later that year, the party opposed Brett M. Kavanaugh’s nomination to the Supreme Court after he was accused of sexual assault when he was in high school.

Biden told reporters at the time that society should generally presume a woman alleging sexual assault is telling the truth: “For a woman to come forward in the glaring lights of focus, nationally, you’ve got to start off with the presumption that at least the essence of what she’s talking about is real, whether or not she forgets facts, whether or not it’s been made worse or better over time,” he said.

There are mixed perspectives in the Democratic Party about how to approach the accusations against Biden, six months before the presidential election. The main question Democrats seem to be struggling with: How do they convey caution about an accusation while also being supportive of a woman’s claim?

Biden is in the process of searching for a vice presidential candidate, who he has promised will be a woman, and some of the potential candidates have focused their comments on how they believe women have the right to be heard while in the next breath defending Biden.

Sen. Kamala D. Harris (D-Calif.) said in an interview with the San Francisco Chronicle that Reade “has a right to tell her story. And I believe that, and I believe Joe Biden believes that, too.”

“I believe women deserve to be heard, and I believe that has happened here,” Stacey Abrams said in a statement to The Post. “The allegations have been heard and looked into, and for too many women, often, that is not the case.”

“I think this case has been investigated,” Sen. Amy Klobuchar (D-Minn.), who has worked to bring sexual assault cases to light, said on MSNBC. “I know the vice president as a major leader on domestic abuse. I worked with him on that.”

Michigan Gov. Gretchen Whitmer (D), who has said she was sexually assaulted in college, told NPR when asked if this allegation concerned her: “Well, I think women should be able to tell their stories. I think that it is important that these allegations are vetted, from the media to beyond.”

Sen. Kirsten Gillibrand (D-N.Y.), one of the first senators to say Franken needed to go, reiterated that she believes women need to be heard in these situations and that she supports Biden. She told The Post: “Vice President Biden has vehemently denied these allegations, and I support Vice President Biden.”

House Speaker Nancy Pelosi (D-Calif.), said Thursday on MSNBC that she is “satisfied” with how Biden has responded.

Trump has given statements that range from cast doubting doubt on the accusation, saying that it could be a “false accusation,” to saying Reade “seems very credible,” and to trying to accuse Biden of dismissing the allegation: “I mean, his choice of words weren’t very good when he, you know, dismissed the allegation,” he told the New York Post in an interview Monday. “But he’s got to fight his own battles, and we’ll see how he does.”

His campaign has focused much of its commentary on what they see as a double standard in how Biden is being treated by his supporters and the media as compared to other accused men like Kavanaugh. After Biden’s interview, the campaign issued a statement saying Biden had not sufficiently addressed the allegations, and charging him and his supporters with hypocrisy.

The double standard exhibited by Biden, prominent liberal women’s groups, and Democrat elected officials – some of whom want to be Biden’s running mate – is glaring and cannot be allowed to stand. There will be a great temptation among Biden’s supporters to take his lackluster interview performance and declare ‘case closed’ and move on. We do not know what, if anything, was done to Tara Reade, but there cannot be one set of rules for Joe Biden and another set for everyone else.

Donald Trump Jr. has shared Reade’s allegation on social media and given interviews about how he thinks it’s troublesome. Trump Jr. and Trump’s campaign manager, Brad Parscale, have accused journalists of not covering the allegation.