Hillary Clinton

Democratic presidential candidate Hillary Clinton reacts to supporters after speaking at a campaign rally at the Iowa State Historical Museum, Monday, Jan. 4, 2016, in Des Moines, Iowa. (AP Photo/Charlie Neibergall)

(Charlie Neibergall)

So you might have heard by now that Democratic presidential frontrunner Hillary Clinton has some peculiar email habits.

And even as the former First Lady, U.S. Senator and Secretary of State is racking up primary wins on the campaign trail, the half-dozen inquiries and legal proceedings is a headache that just won't go away.

Chief among them, as The New York Times reports, is an FBI probe of whether classified information was sent through Clinton's home-built, private server. The Times reports that the FBI could move to questions Clinton's closest aides, and perhaps even Clinton herself, within weeks.

And all that spells trouble for Clinton. Even though she appears to have the nomination locked up, the former SoS will still face a bruising general election fight. And Republicans are sure to make the ongoing email scandal an issue.

Here are five reasons why the email scandal is a problem for Clinton:

1. It's a trust thing: The email flap highlights the ongoing trust issues that Clinton faces among voters. After last month's New Hampshire primary, exit polls found that nearly a third of Democratic voters said honesty was the biggest factor driving their choice of candidate. As The Washington Post reports, of that bloc, Clinton lost to Sen. Bernie Sanders 92-6 percent. And last November, in a McClatchy-Marist survey, nearly 7 in 10 Americans thought Clinton acted either unethically or illegally by using a private server while she was Secretary of State.

2. That guy who just got immunity: On Thursday, the Justice Department announced it had granted immunity to a former State Department staffer who worked on Clinton's private email server. The Washington Post reported that the FBI had "secured the cooperation of Bryan Pagliano, who worked on Clinton's 2008 presidential campaign before setting up the server in her New York home in 2009." And what Mr. Pagliano has to say could certainly spell trouble for Clinton.

3. Clinton's attitudes about transparency say a lot about how she might govern: As Newsweek reported last year, while Clinton may not have violated the letter of the Freedom of Information Act, she certainly violated its spirt: "Had Clinton used a State Department address for email, her communications would presumably be subject to the Freedom of Information Act. They could then be requested by journalists or other members of the public. However, since Clinton used a private server, which is not subject to the FOIA, journalists won't be able to request them," Newsweek reported. Speaking to NPR, John Wonderlich of the Sunlight Foundation added that " "the spirit of the law is--and our expectations for public service--are public servants use their official email accounts." Clinton's apparent disdain for transparency is a worrisome sign for her putative administration.

4. She erased the historic record for her own convenience: This might seem like a minor quibble, but as we've noted before, it's still a big deal. By letting Clinton make the call on what emails could be released and which could not, she's permanently altered the historic record. We may now never know how Clinton's decisions about her email have reshaped the narrative of American foreign policy in the mid-2000s. As we noted in 2015, it's safe bet the record has been specifically tailored to make her look good in the eyes of history.

5. Did we mention that it's a trust thing? True, Clinton cleaned up on Super Tuesday, winning seven of 11 states. But exit polling in the SEC primary continues to highlight the trust issues she has with voters. In a CNN/ORC poll released just before last week's Democratic primary in South Carolina, more than half of all voters (55 percent) viewed Clinton unfavorably. It was the highest unfavorable rating that Clinton had registered since the question was first asked in March 1992.

What do you think? Have your say in the comments.