There has always been a contingent in the Democratic base who is not on board with the Clintons. They’re the people who are currently trying to draft Elizabeth Warren into the 2016 race or hoping for, at minimum, a primary fight where Hillary must defend her “inevitability” for the nomination. With the recent flap over her State Department emails, it appears some Democratic hopefuls see the door opening a little further for the chance at a serious primary challenge.

Report from the CSMonitor:

Former Gov. Martin O’Malley (D) of Maryland isn’t running for the Senate seat being vacated by Sen. Barbara Mikulski (D), who is retiring at the end of her term.

“I am hopeful and confident that very capable public servants with a desire to serve in the Senate will step up as candidates for this important office,” the former governor said Tuesday, in a statement. “I will not be one of them.”

Mr. O’Malley, it appears, is keeping his eyes on the prize: the presidency. O’Malley has been quietly preparing for months to run for president, despite the appearance that Hillary Rodham Clinton has the Democratic nomination all but locked up, without even having announced.

Now, the inevitability argument may be fraying a bit. Mrs. Clinton has faced damaging headlines about foreign government donations to the Clinton family foundation, in apparent violation of ethics rules set up during her tenure as secretary of State. On Monday night, The New York Times reported that Clinton used a personal e-mail account to conduct government business while at the State Department, in possible violation of federal rules on the e-mails of government officials.

Which brings us back to O’Malley. If he proceeds with a run for the Democratic nomination, he has his work cut out. He is largely unknown outside of Maryland and doesn’t have any of the cachet or cool of a Barack Obama, circa 2007. And he was succeeded by a Republican, now-Gov. Larry Hogan, who beat O’Malley’s lieutenant governor, Anthony Brown, in an upset.

I can envision this scenario as candidates like O’Malley just waiting for the damn to break and provide them reasons to promote themselves and argue against Hillary. After all, some of them are surely fearful that if they do get on the wrong side in this primary contest, they’d be left out of a future Clinton administration. If just enough of the armor begins to fold, it may entice more of them, Joe Biden included, to begin launching a real challenge. In fact, even Al Gore is visiting Iowa soon.

O’Malley is flawed in his own right but he is a new face on the national scene. He’d have an uphill battle but his recent moves signal that the time may be reaching a peak when other Democrats are seeing the opening they need.