Democrats' advantage over Republicans in partisan affiliation is way down from 2008 as white voters have turned against them, according to a poll released Friday by the Pew Research Center.

While minority voters continue to support Democrats in large numbers, what was just a two-point Republican edge among whites in 2008 has grown to a 13-point advantage today. Republican gains among white voters are "particularly pronounced among the young and poor," according to the report.

White voters under age 30 now break for Republicans by an 11-point margin; in 2008 they broke for Democrats by a seven-point margin. This could spell trouble for President Obama's reelection efforts, as he capitalized on a coalition of minority voters and younger white voters to become president.

Part of the calculus might be the economy: Young adults have the highest rate of unemployment of any age group.

Democrats still hold a 47-44 percent advantage in partisan affiliation, counting those who lean to one party or another, according to the poll. But because minorities tend to vote at lower rates, that slight advantage is likely not enough to translate to wins at the ballot box.