Voters are now more likely to select Republican candidates over their Democratic opponents to fill House seats in 2010, according to a poll.

Gallup's latest numbers, released Wednesday, spell some early trouble for congressional Democrats. The majority party for months maintained a slim lead over the GOP in measures of generic ballot preference, but its six point advantage less than six months ago has become a four-point disadvantage in November.

Now, 48 percent of voters say they plan to choose a Republican candidate in 2010, compared to only 44 percent who said they would select a Democrat. It is the first time this year Republicans have held a lead over Democrats on the generic ballot question.

A closer look at the cross-tabs also reveals that independents are growing more fond of the GOP: More than half of registered independent voters indicated in the poll they plan to select a Republican candidate in 2010. Just under one-third, however, said they would opt for a Democrat.

That number marks a serious shift in political mood: The GOP possessed a mere one-point advantage among independents when Gallup asked this question in July, but Republicans can now boast a more than 20 point advantage among this same group.

Taken together, Gallup predicts an exceptionally tough year for Democrats, barring serious changes to the electoral landscape. According to pollsters, the GOP does not typically hold such leads over Democrats on generic ballot questions, with two notable exceptions -- 1994 and 2002, both years during which Republicans performed very well in congressional elections.