Democrats in recent weeks weighed whether to abstain from involvement in House Republicans' new Benghazi investigative committee, labeling it an unnecessary probe into questions that have already been answered.

The American people disagree.

A new Washington Post-ABC News poll shows a majority of Americans -- 51 percent -- approve of the new panel, while 42 percent disapprove.

Those supporting the new investigation include 72 percent of Republicans (not surprisingly), but they also include 31 percent of Democrats and a majority -- 52 percent -- of political independents.

The reason Americans want an investigation? Because they don't believe Democrats when they say that all the questions have been answered.

In fact, the number of Americans who think the Obama administration has covered things up (58 percent) is even larger than the number who want the investigation (51 percent). Americans say 58 to 32 percent that Obama has covered things up rather than being honest about what happened. That's a bigger gap than last year, when it was 55 to 33 percent (though the shift is not statistically significant).

They also don't think former secretary of state Hillary Rodham Clinton is anywhere close to blame-free. The poll shows 50 percent of Americans disapprove of Clinton's handling of the situation, with just 37 percent approving.

Previous polling has shown support for the new investigation is even higher, so the totality of the polls suggests that the new probe has a mandate from the American people.

Now, that doesn't mean that it has a mandate to do whatever it wants. Indeed, GOP leaders didn't necessarily want to insert this wild card into a 2014 election landscape in which they already had the advantage and were doing just fine when the sole focus was Obamacare. The launching of the panel certainly opens the door to overreach.

But the polls demonstrate that Democrats can't credibly suggest that the mere existence of this Benghazi panel is superfluous and unnecessary. A majority of the American people believe in its purpose, which gives it validity from the outset.

From here, it's up to Democrats and the administration to recognize that -- and Republicans to maintain their mandate.

It's been almost two years, but the fallout from the September 2012 attack on a U.S. consulate in Libya is making new headlines. And it’s all thanks to an e-mail. (Pamela Kirkland/The Washington Post)