Hillary Clinton told ABC’s David Muir on Tuesday that setting up a private e-mail server while she was secretary of state “was a mistake. I’m sorry about that. I take responsibility.” (Jay Laprete/AP)

“I’m sorry.”

It took Hillary Clinton the better part of six months to say those two little words about her decision to set up a private e-mail server after she was nominated as secretary of state in late 2008.

After a series of “I’m sorry if people were offended” non-apologies, Clinton finally delivered the no-frills version in an interview with ABC’s David Muir this past week. “In retrospect, as I look back at it now, even though it was allowed, I should have used two accounts,” she acknowledged. “One for personal, one for work-related e-mails. That was a mistake. I’m sorry about that. I take responsibility.”

So, that’s a start! Except that the damage to Clinton’s campaign caused by persistent questions about why she had the server in the first place, and why she didn’t initially give it to the Justice Department, remains.

Polls this past week in Iowa and New Hampshire showed Clinton running even with or behind Sen. Bernie Sanders (Vt.) in the Democratic presidential race; perhaps more ominous is that 3 in 10 Iowa Democrats said that the words “honest” and “trustworthy” don’t apply to her.

On top of it all is the looming figure of Vice President Biden, who continues to ponder entering the 2016 race as each day brings more bad news for Clinton.

The problem for Clinton is that this e-mail brouhaha is a self-inflicted wound. She never needed to use a private server. And once it was revealed that she had, she could have come out far earlier with an apology and deflected much of the damage.

Hillary Clinton, for making “sorry” the hardest word to say, you had the worst week in Washington. Congrats, or something.

Each week, Chris Cillizza awards the worst week in Washington to an inhabitant of Planet Beltway who stands out for all the wrong reasons. You can check out previous winners or e-mail Cillizza with candidates. You can also read more from Outlook and follow our updates on Facebook and Twitter.