Tobin previously had a lead of about 500 votes. He has 35 percent of the vote to Kiehne’s 36 percent.
Rep. Adam Kwasman is in last place with 28 percent, trailing Tobin by about 2,200 votes.
But with votes still being counted, it will likely be a long night – and maybe longer – before the primary can be called and Democratic U.S. Representative in Congress Ann Kirkpatrick will know who she will face in November.
The district is one of the largest congressional districts in the country, and spans from Arizona’s northwest corner, through the Grand Canyon and down the state’s border with New Mexico to the northern edges of Pima county.
CD1 leans slightly Democratic, but voters chose Republican presidential nominee Mitt Romney over President Obama in the 2012 election. Kirkpatrick is a top target for national Republicans in November.
Tobin was seen as the early frontrunner in the race, and has touted himself as the only Republican with the chops to take on Kirkpatrick in November. However, doubts emerged about his campaign after he struggled to raise the money many expected he would, and he failed to separate himself from his Republican opponents.
Tobin was outspent by Kiehne, who mostly self-funded his campaign, and spent a total of $600,000 in his campaign as of Aug. 6. Tobin spent $520,000 in the race.
But Tobin had a series of last-minute boosts from outside groups spending to support him. The U.S. Chamber of Commerce spent $300,000 on TV advertisements for Tobin, who was the only Republican candidate not airing TV ads as of the middle of August. Preserve America’s Future PAC also spent $25,000 on his behalf this month, while Main Street Advocacy spent $40,000 on his behalf last week.
Democrats have been attacking Tobin since April. The Democratic House Majority PAC, which fears him as the strongest of the three Republicans in a general election, spent more than $250,000 for commercials attacking him as an “insurance executive… (who gave) special tax breaks to insurance companies.”
Kwasman, meanwhile, has been even less successful than Tobin at fundraising, spending only $255,000 in his campaign. Outside groups have also come to his aid. The Hometown Freedom Action Network PAC spent $220,000 on commercials supporting Kwasman and opposing Tobin and Kiehne. Kiehne has not received any support from outside groups.
And while the Republicans have been spending their money as fast as it comes in, Kirkpatrick has the luxury of an uncontested primary, and has stockpiled more than $1.4 million for the November election, making her a formidable candidate for whichever Republican emerges victorious tonight.
The Republican primary has been marred by a series of high-profile gaffes by all three candidates.
Most recently, Tobin reaped negative national media coverage after suggesting that unaccompanied minors from Central America could be carrying the Ebola virus into the United States.
The gaffe, which was mocked by liberal media outlets, came after Tobin had condemned Kwasman and Kiehne as jokers who could embarrass the state if nominated in the race.
Kwasman was featured on Comedy Central’s “The Colbert Report” after mistaking YMCA campers for migrant children, and claiming the campers “were sad, too” when confronted by the error.
Kiehne gained national headlines when he made the outrageous claim that 99 percent of mass shootings were committed by Democrats.