Gap closing: McCain 48, Hayworth 41

Following the announcement that Sarah Palin would campaign for his reelection, McCain opened up a 53% to 31% lead over Hayworth in January. The two men were in a near tie in November.

But now Hayworth, a former congressman turned popular local talk radio host, is a formal candidate, and anti-immigration activist Chris Simcox has quit the race and endorsed him. For McCain, the new numbers also show him dropping again below 50%, and incumbents who poll less than 50% at this stage of a campaign are considered potentially vulnerable.