Republicans are favored by 49 percent of likely voters compared to 43 percent for Democrats, said the poll, which was published by the Washington Post.
A Washington Post-ABC News poll last month showed Republicans with 53 percent support versus 40 percent for Democrats, who are fighting to keep their majority in Congress.
The findings were in line with recent polls showing Democrats making slight gains in terms of voter preferences for Congress and voters’ enthusiasm for the parties, although most surveys still show the Democrats trailing Republicans.
The Republicans’ advantage on the question of which party voters say they will support in the November 2 election has been cut in half, the poll showed.
Democrats also gained some ground on the question of which party people trust most to handle big issues such as the economy and health care, the poll said.
Forty-one percent of respondents said they trusted Democrats to do a better job of coping with the main problems the United States faces over the next few years, while 39 percent favored the Republicans.
Fifteen percent said they did not trust either party to do the job.
Nearly three-quarters of voters who identified themselves as Republicans called the 2010 elections more important to the country than previous elections in their lifetime, the newspaper reported.
Voter dissatisfaction with lawmakers in Washington remained high, with Congress getting a 23 percent approval rating in the poll. Congressional Democrats have a disapproval rating of 61 percent, while 67 percent disapprove of Republicans.
One third of voters think Tea Party candidates would change the culture of Washington in a positive way, and about 15 percent said they strongly supported the populist conservative movement, the newspaper said.
The poll of about 1,000 people was conducted between September 30 and October 3. The margin of sampling error was plus or minus 3.5 percentage points.
Copyright © 2010 Reuters Ltd.