DES MOINES, Iowa – Seven Republican presidential contenders will try to use Thursday's debate, sponsored by Fox News and the Washington Examiner, in the leadoff caucus state of Iowa to cast themselves as the strongest alternative to one rival: front-runner Mitt Romney.

A Fox News Poll released Wednesday showed that the former Massachusetts Gov. remains Republican primary voters’ preferred candidate.

But all risk being overshadowed by one Republican who won't be on the stage -- Texas Gov. Rick Perry, who has signaled he's likely to join the field in the coming days and will visit the early nominating states of Iowa, New Hampshire and South Carolina this weekend...