Rasmussen Reports released a telephone survey today that shows former Massachusetts Gov. Mitt Romney with 39 percent support among likely Republican primary voters in Arizona.

Santorum has closed a once wider gap since he now has the support of 31 percent of likely voters. 

Former U.S. House Speaker Newt Gingrich trails far behind them both with 15 percent of likely voters and U.S. Rep. Ron Paul, R-Texas, has about 7 percent support. That's close to the 5 percent who remain undecided in the primary election, which will be held Feb. 28.

The poll of 750 likely voters was held Thursday and has a smapling error of 4 percent.