Rep. Michele Bachmann's (R-Minn.) 2012 opponent, wealthy businessman Jim Graves (D), appears to be gearing up for a rematch.

Graves, who came within 5,000 votes of Bachmann last election, indicated interest in running again in an email to supporters.

"I know that the work we started last year, well, it isn't over," he wrote after attacking Bachmann for voting against the Violence Against Women Act.

Graves said last month that he'd decide on the race by April 1.

While the district is heavily Republican, Bachmann ran well behind Mitt Romney there in 2012 and could be vulnerable again, especially against a centrist self-funder like Graves.

However, much of her vulnerability was due to a perception she'd abandoned her district to run for president, a problem that may have lessened with time. She's also one of the strongest fundraisers in the House, giving her a big boost in any reelection battle.