A new Republican poll showed the party’s Senate nominee in Indiana, state Treasurer Richard Mourdock, with a 3-point lead in the race.

Mourdock had 45 percent, while Rep. Joe Donnelly (D) took 42 percent in the survey paid for by the GOP candidate’s campaign. Roll Call obtained a copy of the poll’s accompanying memo.

Just two weeks ago, a bipartisan poll from Howey Politics Indiana gave Donnelly a 2-point edge in the race. But in both polls, the candidates are within the margin of error.

The surveys underscore just how competitive the Senate race has become. Outside groups have bombarded the Hoosier State’s airwaves since early September. Roll Call rates this race as a Tossup.

In the Senate race poll, a third-party candidate received 4 percent, while 8 percent reported they were undecided.

Mitt Romney boasted a 16-point lead in the state over President Barack Obama in the survey.

Also according to the memo, Republicans made up 43 percent of the sample, while Democrats and independents were 33 percent and 23 percent, respectively.

The McLaughlin & Associates survey took the opinion of 600 likely voters Oct. 3-4 — the days that sandwiched the first presidential debate. The margin of error was 4 points.