A big part of politics is appearances and perceptions. If something looks bad, people will likely conclude it is bad — even if there’s no actual evidence or proof of its relative badness. Politicians know this; it’s why they don’t wear funny hats or get in tanks (anymore).

And it’s why Bill Clinton and Attorney General Loretta Lynch should have known better when they huddled privately at the Phoenix airport last week. Lynch is the nation’s top cop and, as such, oversees the FBI, which is conducting an investigation into whether Hillary Clinton or any of her associates broke the law in setting up a private e-mail server for her electronic correspondence during her four years as secretary of state. Meeting privately with the former president of the United States who also happens to be Hillary Clinton’s husband looks really, really bad.

Lynch insisted in the wake of the meeting that it was purely cordial, saying Wednesday that the two spoke about “his grandchildren and his travels and things like that.” She added that the e-mail probe never came up.

That answer, not surprisingly, didn’t satisfy lots and lots of Republicans — and even some Democrats. “I think she should have said, ‘Look, I recognize you have a long record of leadership on fighting crime but this is not the time for us to have that conversation,’ ” Delaware Democratic Sen. Chris Coons said of Lynch in an interview with CNN. ” ‘After the election is over, I’d welcome your advice.’ ”

Lynch bowed to the public pressure caused by her impromptu meeting Friday morning, announcing that she will accept whatever recommendation federal prosecutors make in the e-mail case. Lynch repeatedly acknowledged in an interview with The Washington Post’s Jonathan Capehart at the Aspen Ideas Festival in Colorado that her meeting with Bill Clinton had cast a shadow over the investigation. After much prodding from Capehart, she even basically acknowledged the meeting never should have happened in the first place.

“I certainly wouldn’t do it again,” she said.

While a Justice Department official who spoke to The Post insisted this was standard operating procedure — and Lynch insisted this determination had already been made prior to her meeting with Bill Clinton — Lynch’s announcement was clearly a direct response to questions raised by her meeting with the former president earlier this week. She admitted it was, noting that details about the investigative process are rarely shared publicly.

Lynch handled tough questions from Capehart about as well as she could have. But that still isn’t likely to change much of anything. If the FBI now returns something short of an indictment for Clinton and her top aides, Republicans will cite the Lynch-Bill Clinton meeting as evidence that the process was tainted from the start, that a Democratic administration simply can’t be trusted to look deeply into the person the party is preparing to nominate for president. (Republicans, including Texas Sen. John Cornyn, are already calling for the appointment of a special prosecutor in the e-mail case.)

There might have been no way — in lots of peoples’s eyes — that Clinton could be fully exonerated on the e-mail controversy even before this Bill-Lynch meeting. But, if there ever was that chance, it’s gone now. It’s like playing a basketball game in which you felt like the refs gave your team a hard time and then finding out that the other coach had dinner with them the night before the game. It’s possible, of course, that nothing was even mentioned about the impending game; they might all just have been in the same restaurant and sat together for a drink or whatever. But no one would ever be able to convince you that there wasn’t something nefarious going on at that dinner. And, it just plain looks bad.

Increasingly, the Clintons’ defense on the e-mail story is summed up in two words: “Trust us.”

Trust Hillary Clinton that the thousands of e-mails she decided to delete as totally personal were totally personal and didn’t mention work at all — despite the fact that a State Department e-mail release earlier this week fundamentally undermines that argument.

Trust Bill Clinton (and Lynch) that their huddle in Phoenix was purely friendly and never touched on the e-mail server investigation.

Trust Hillary Clinton that the only reason she set up the server in the first place was out of “convenience.”

Trust them both that this whole thing is simply a Republican witch hunt and/or a trumped-up “scandal” created by a bored and adversarial media.

The problem with the “trust us” defense? Poll after poll suggests that a majority of the public simply doesn’t trust them – saying that the words “honest” and “trustworthy” don’t apply to Clinton. In an NBC-Wall Street Journal poll released this week, 41 percent said that Donald Trump would be better about being “honest and straightforward,” while just 25 percent said Clinton would be better on those things. (One in three said neither candidate would be good on those traits.) And, according to the latest Washington Post-ABC News poll, six in 10 registered voters believe Clinton has handled her e-mail issues poorly.

This whole mess created by Lynch and Bill Clinton will only make those numbers worse, further exposing Hillary Clinton’s biggest weakness in the eyes of voters. And she has her husband to “thank” for it.

Chris Cillizza writes “The Fix,” a politics blog for The Washington Post.

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