The National Republican Congressional Committee spent more than $122,000 this week on a series of ads supporting the moderate state representative. Ed Patru, a spokesman for the NRCC, says Huffman is the only GOP primary candidate the committee has bought advertisements for this year.

It could be a sign of growing fears about what pundits have said all along about the competitive Arizona race: Conservative illegal immigration hawk Graf might not match up well against moderate state Sen. Gabrielle Giffords, who now appears to be the leading Democratic contender.

The move builds on Huffman's record in the race as a Republican establishment favorite. Kolbe, an 11-term congressman, endorsed Huffman in May. And the political action committees led by Speaker of the House Dennis Hastert, House Majority Leader John Boenher, and House Majority Whip Roy Blunt each have made a $5,000 contribution to Huffman's campaign in the past week.

The advertising buy sparked harsh words from Graf and Mike Hellon, a former GOP state chairman who is considered another major contender in the five-way primary race.

"They're going to try to re-create Steve Huffman," Graf said of the national Republicans at a candidate forum Wednesday night. Graf also emphasized he represented "real change" and that Giffords and Huffman voted together 90 percent of the time in the Legislature, making them virtually indistinguishable.

Hellon told a local newspaper that the flurry of money indicated Huffman was "bought and paid for" by Washington, D.C.

The latest gauge of the race, a Nogales International/Wick Communications poll taken last week, showed Graf with the support of 36 percent of Republicans compared with Huffman's 13 percent. Hellon trailed with 10 percent.

--Angie C. Marek