Republican Terry Branstad continues to hold a double-digit lead over Democratic incumbent Chet Culver in Iowa’s gubernatorial race.

The latest Rasmussen Reports statewide telephone survey of Likely Voters shows Branstad picking up 52% support, while Culver gets 36% of the vote. Eight percent (8%) prefer another candidate, and four percent (4%) are undecided.

Most voters in the state view Branstad as a conservative and Culver as a liberal. Troubling for the incumbent is that nearly half (47%) of Iowa voters think his political views are extreme, compared to 39% who put them in the mainstream. Branstad’s views, by contrast, are regarded as mainstream by 57% and extreme by just 31%

Just after he won a three-way GOP Primary contest in June, Branstad, who previously served as governor from 1983 to 1999, jumped out to a 57% to 31% lead. But with the exception of that post-primary bounce, the Republican has earned 52% or 53% of the vote in surveys since February. Culver has earned 36% to 38% support in that same period.

Culver was first elected governor in 2006 with 54% of the vote.

(Want a free daily e-mail update? If it’s in the news, it’s in our polls). Rasmussen Reports updates are also available on Twitter or Facebook.

The survey of 500 Likely Voters in Iowa was conducted on August 5, 2010 by Rasmussen Reports. The margin of sampling error is +/- 4.5 percentage points with a 95% level of confidence. Field work for all Rasmussen Reports surveys is conducted by Pulse Opinion Research, LLC. See methodology.

Thirty-seven percent (37%) now approve of the job Culver is doing as governor, down four points from June, but 61% disapprove.

Branstad is backed by 87% of Republicans, while Culver is supported by 78% of Democrats. The Republican leads by more than two-to-one among voters not affiliated with either major political party.

Seventy-two percent (72%) of Iowa voters view Branstad as politically conservative, while Culver is seen as politically liberal by 57%. Twenty-six percent (26%) rate the governor as a moderate.

Branstad is viewed Very Favorably by 28% of Iowa voters and Very Unfavorably by 20%.

Thirteen percent (13%) have a Very Favorable opinion of Culver, while 40% view him Very Unfavorably, up nine points from June.

Both candidates are well-known in the state, but at this point in a campaign, Rasmussen Reports considers the number of people with a strong opinion more significant than the total favorable/unfavorable numbers.

Just over half of Iowa voters (51%) give their personal finances good or excellent marks, which is higher than results found nationally. Only 11% rate their finances as poor. But just 27% in Iowa say their finances are getting better these days, compared to 40% who say their finances are getting worse.