U.S. Republican presidential candidates are gathering for a televised debate in the central state of Iowa Thursday ahead of a “straw poll,” or test vote, that could help identify the frontrunners for next year's party nomination.

Eight candidates are expected to take part in the debate, including former Massachusetts governor Mitt Romney, who is seen so far as the leading candidate. Also participating are U.S. Representatives Michele Bachmann and Ron Paul, former Minnesota governor Tim Pawlenty, and former U.S. ambassador to China Jon Huntsman.

Not appearing at the event is Texas Governor Rick Perry, who is expected to join the Republican race soon with the potential to appeal to both social and economic conservatives within the Republican Party.

Candidates' performances in the debate could have a big influence on Saturday's straw poll results, and possibly set the stage for success in next year's presidential caucuses.

In 2008, then-candidate Barack Obama used his victory in the Iowa caucuses as a springboard to best his rival Hillary Clinton in the battle for the Democratic Party nomination and the presidency.