Rick Perry (File)
Rick Perry (File)

The race for the Republican party's nomination to oppose U.S. President Barack Obama in the 2012 presidential election has been shaken up with one governor entering the race and one former governor dropping out.

Texas governor Rick Perry announced his candidacy on Saturday, the same day the midwestern state of Iowa held what is called a "straw poll," seen as an early indication of voters' preference.

That test vote was narrowly won by Congresswoman Michele Bachman of Minnesota, with Texas Congressman Ron Paul coming in second. But the former governor of Minnesota, Tim Pawlenty, finished a distant third and on Sunday he announced he is dropping out of the race.

Bachman, a favorite of conservative Tea Party activists, is considered a top contender for the Republican nomination. She is campaigning on a platform of lower taxes and a smaller federal government. But Perry is seen as a formidable challenger. And although he was not on the ballot in Iowa, he earned more write-in votes (718) than former Massachusetts Governor Mitt Romney, who up to now has been considered the front-runner.

Perry is the longest -serving governor in the nation and the longest-serving in U.S. history.  He became governor in 2000, taking over the post vacated by George W. Bush when he became president.

Iowa's straw vote was held five months before the Iowa caucuses, the first serious vote in the long presidential campaign season.