The Republican nomination race has heated up in recent weeks, as Newt Gingrich has surged into the lead in many key early voting states. But at the same time, GOP voters are becoming less enthusiastic about voting next year—a potentially bad sign for Republicans who desperately need their base to turn out in order to defeat President Obama.

A new Gallup Poll finds just 49 percent of likely Republican voters say they are “more enthusiastic than usual” about voting in the 2012 elections—a nine point drop since late September. The decrease is especially ominous, since the party’s base is presumably paying more attention to the election, with the official kick-off to voting now less than a month away.

Still, Republicans continue to be slightly more enthusiastic about the 2012 campaign, according to the Gallup Poll. That illustrates perhaps the biggest problem facing Obama’s re-election campaign, which is still trying to activate its base of supporters who turned out in historic numbers to back Obama in 2008.