Rep. Michele Bachmann (R-Minn.) trails her 2014 Democratic challenger Jim Graves by two percentage points, according to a new poll.
The two-percentage-point lead is within the poll's plus or minus 4-point margin of error, indicating the race is statistically tied.
Graves announced last month he would seek a 2014 rematch against Bachmann, after losing to the former GOP presidential candidate by 4,300 votes last November.
In a sign of some early concern about her reelection prospects, Bachmann last week reserved approximately $85,000 in TV time across a number of Minneapolis stations.
It's exceedingly rare to see House candidates go on air during non-election years.
Bachmann, who dropped out of the Republican presidential race after a poor showing in the 2012 Iowa caucuses, is facing ongoing ethics questions relating to that campaign, including a possible investigation of former staff in Iowa.
But she'll be tough to beat: Bachmann is one of the strongest fundraisers in the country, and the exurban district she represents went for Republican presidential nominee Mitt Romney by a 15-point margin in 2012.
Even so, the poll showed Bachmann's struggling to hold the approval of voters.
She's seen unfavorably by 51 percent of respondents, while 46 percent view her positively. Graves is seen favorably by 39 percent and unfavorably by 33 percent of respondents, but a full 28 percent are still unsure of how they feel about him.
Graves also posts stronger crossover appeal, with 17 percent support among Republicans, while Bachmann has the backing of only eight percent of Democrats.
The poll was conducted among 500 voters in Bachmann's district on May 15, just before the incumbent went on television with new ads.
Graves, the founder of the AmericInn hotel chain, self-funded much of his last campaign and received almost no support from the national party in the Republican-leaning district.
Even if the Democratic Congressional Campaign Committee gets involved this cycle, he faces a difficult challenge.
Anger in the district at Bachmann for running for president won't be as fresh, and Bachmann has sought the national spotlight less in recent months than she had in the past. Midterm elections also tend to be better for Republicans because of shifting demographics.
In recent weeks, Bachmann has helped relaunch the Congressional Tea Party Caucus and sponsored a bill to repeal ObamaCare.
--This post was updated to reflect Bachmann's position in the poll.