Contenders Spar in Tight Arizona Senate Race

Polls show them both in the lead - and trailing

U.S. Senate contenders Richard Carmona and Jeff Flake clashed Wednesday in their first public head-to-head appearances of the general-election season, with Flake accusing Carmona of retreating from his previously expressed support of President Barack Obama's landmark health-care-reform law and Carmona accusing Flake of flip-flopping on comprehensive immigration reform.

The two rivals also traded barbs over earmarks — Flake's signature issue — and bringing home federal dollars to Arizona, as well as other topics.

The Arizona race has become one of the most closely watched in the nation and could help decide which party controls the Senate.