DES MOINES - It looks like Republican presidential candidates will be debating without their front-runner. Donald Trump hopes to starve his rivals of attention at a critical juncture in the campaign by holding a competing event of his own.

Trump's abrupt decision to boycott the final debate before Monday's Iowa caucuses has added a new layer of uncertainty to a race that has defied political convention. The real estate mogul cites "unfair" treatment from debate host Fox News as his reason for skipping the contest Thursday night in favor of a rally nearby.

Other GOP candidates see Trump's move as a welcome opportunity to emerge from the long shadow the billionaire has cast over the race, while also hoping it might damage his standing with Iowa voters.