Republican presidential candidate Rick Santorum is essentially tied with rival Mitt Romney in Arizona, according to an opinion poll released on Tuesday that points to another possible surprise in the topsy-turvy nominating race.
The Time/CNN poll found Romney ahead of Santorum 36 percent to 32 percent, a lead that is within the 4.5 percentage point margin of error.
Romney had led previous polls by double-digit margins, and Santorum has put little effort into winning Arizona's February 28 primary.
Former House of Representatives Speaker Newt Gingrich won the support of 18 percent, while Texas Representative Ron Paul was at 6 percent.
A loss in Arizona would be a devastating blow for Romney, who faces another crucial February 28 test in Michigan, where his father served as governor. Opinion polls show Santorum leading narrowly there.
Romney, a former Massachusetts governor and private-equity executive, had been expected to win easily in Arizona before Santorum captured the momentum in the state-by-state nominating contest to face Democratic President Barack Obama in the November 6 election.
Romney has a strong campaign organization in the state and the backing of much of the state party establishment, including Senator John McCain, the party's 2008 presidential nominee. Romney's fellow Mormons also make up a large and active voting bloc.
But Santorum, a former Pennsylvania senator, has pulled ahead in national polls after winning contests in Missouri, Minnesota and Colorado on February 7. Arizona officials say there has been rising interest in Santorum even though he has not yet run television ads, made campaign appearances or set up a local organization.
Some 58 percent of those surveyed said they had definitely settled on a candidate, while 34 percent said they might change their mind.
Santorum would be taking a risk by competing hard in Arizona. The state's winner-take-all system means even a close second-place finish would earn him none of the state's 29 delegates to the August nominating convention. To secure nomination a candidate would need 1,144 delegates.
The four candidates will be in the state for a debate in Mesa on Wednesday.
The poll found Romney leading among women and more affluent voters. Santorum, a devout Catholic, led among evangelicals.
The poll was based on a survey of 467 likely voters conducted between February 17 and February 20.
(Editing by Mohammad Zargham)