U.S. voters prefer Democratic presidential nominee Barack Obama over Republican nominee John McCain by 51 percent to 46 percent, a CNN poll indicated.

The CNN/Opinion Research Corp. Poll released Monday found that twice as many registered voters blame Republicans as fault Democrats for the turmoil in the financial markets. Forty-seven percent of registered voters said Republicans shoulder a larger share of the blame while 24 percent blamed Democrats, CNN said.

Twenty-one percent said both parties are equally to blame and 8 percent said neither party was to blame for the crisis.

The poll indicated that 49 percent of those surveyed said Obama would do a better job in an economic crisis, while 43 percent said McCain would do better. Obama had a 10-point lead on the question of which candidate would do a better job with the economy overall.

CNN said Obama was gaining support in two core McCain constituencies -- men, who favor Obama by a slim margin, and seniors.

The poll, conducted Friday through Sunday, was based on interviews with 1,020 participants, including 909 registered voters and 697 likely voters. The margin of error was 3 percent.