PHOENIX -- The departure of one of the three top-tier challengers to incumbent Jan Brewer apparently isn't helping the two remaining survivors.
A survey of 707 likely Republican voters released Tuesday found that neither Buz Mills nor Dean Martin was able to capitalize on the fact that John Munger pulled out of the race.
In fact, the Rasmussen Reports poll found Brewer stronger than ever, picking up the support of 61 percent of those questioned. A month earlier she had the backing of just 45 percent.
By contrast, Mills and Martin, who each had been the favorite of 18 percent of those questioned in June, actually lost support. The new poll shows Mills at 16 percent, with Martin picking up the backing of 12 percent.
Pollster Scott Rasmussen did not ask about Matthew Jette, the fourth Republican in the race. But there is little to suggest his presence has any effect: Only 2 percent said they wanted to vote for someone other than the three contenders listed.
Brewer has staged what can only be considered a remarkable turnaround in political fortune, bolstered both by her decision to sign a tough new law aimed at illegal immigrants as well as her backing of a temporary sales tax hike that voters overwhelmingly approved. As recently as March she was in a virtual dead heat with all contenders.
Conversely, Mills' campaign spending -- in excess of $2.3 million as of the end of May -- has done little to gain support.
That same group of GOP voters still gives John McCain the edge in retaining his U.S. Senate seat.
The incumbent was the choice of 47 percent of those who responded. Former Congressman and radio talk show host J.D. Hayworth had just 36 percent, with Navy veteran and apparent Tea Party favorite Jim Deakin picking up the backing of 7 percent.
But Rasmussen said while McCain has maintained his lead over Hayworth, his chances of winning still remain at risk.
"Any incumbent who earns less 50% support is considered potentially vulnerable,' Rasmussen said, noting McCain "has been hovering around that mark all year.'
And Rasmussen said McCain's level of support at this point in the Arizona race is similar to that of another veteran senator: Republican-turned-Democrat Arlen Specter of Pennsylvania.
"Specter, ultimately defeated in the state's Democratic primary by Joe Sestak, led in just about all early polling but could never get much above the 50-percent level of support,' Rasmussen said.
Both survey questions were asked June 16 and have a margin of error of 4 percentage points.