WASHINGTON (Reuters) - Fred Thompson, an actor and former senator who has not formally entered the 2008 White House race, leads Republican presidential contenders for the first time, according to a Rasmussen poll released on Tuesday.
Thompson held a statistically insignificant one percentage point lead over former New York Mayor Rudolph Giuliani in the national poll of likely Republican primary voters, 28 percent to 27 percent. It was the first time all year anybody but Giuliani has led the 10-strong Republican field.
Thompson and Giuliani were tied at 24 percent each in the poll one week ago.
Some other polls show Thompson moving into a solid second place in the Republican race, ahead of established candidates like Arizona Sen. John McCain and former Massachusetts Gov. Mitt Romney.
Thompson formed a "testing the waters" presidential committee in his home state of Tennessee earlier this month, and is expected to formally enter the race in July.
His candidacy has been fueled by Republican dissatisfaction with the current field, particularly among conservatives.
The star of numerous Hollywood movies and the "Law and Order" television series served eight years in the Senate.
The Rasmussen poll of 618 likely Republican primary voters, conducted on June 11-14, had a margin of error of plus or minus four percentage points.