More Americans believe that Republicans can do a better job on both the economy and national security, a poll released Friday showed.

Asked which party is best able to keep the United States prosperous, 48 percent chose the GOP while 39 percent chose Democrats. The numbers were similar on protecting the nation from external threats: Forty-nine percent favor Republicans versus 38 percent for Democrats, according to the Gallup poll.

The party that controls the White House historically takes a major hit in the polls, a political rendering of “the grass is always greener.” But the lack of faith in Democrats’ abilities bodes poorly for the party in 2012 as it tries to reelect President Obama, wrest back control of the House and keep the GOP from overtaking the Senate.

Americans surveyed also said they saw the GOP as better able to deal with whatever problem they identified as the most important.

But Republicans have reason to be wary as well: Support for their members of Congress is in the tank, and the new poll showed 55 percent of Americans think both parties do such a poor job that a third party is needed.

Democrats polled better than Republicans on keeping the country prosperous from 2003 until 2009, which included most of former President George W. Bush’s tenure. A year into Obama’s first term, the positions flipped.

The survey of 1,017 adults across the United States was conducted Sept. 8-11 and had a margin of error of plus or minus 4 percentage points.