Central Oklahoma voters will hit the polls Tuesday for the second time in a month, this time to choose between two Republicans in the runoff to replace Rep. Mary Fallin (R), the gubernatorial nominee.

Former youth camp director James Lankford finished with 613 more votes than former state Rep. Kevin Calvey in the July 27 primary, giving Lankford 34 percent of the vote to Calvey’s 32 percent. Since none of the seven Republicans crossed the 50 percent threshold, the top two candidates were bound for Tuesday’s runoff.

The differences between Calvey and Lankford have less to do with policy than with background. Lankford is in his first campaign and got the support of all but one of his primary opponents. Calvey, an attorney, served in the Oklahoma House from 1998 to 2006. He was endorsed by the Club for Growth and the Oklahoma Rifle Association, the state affiliate of the National Rifle Association. Through Aug. 4, Lankford raised $473,000 and had no debts, while Calvey raised $972,000 but had $301,000 in debt, including a $250,000 loan from himself.

The low-turnout runoff is hard to predict. In the primary, Calvey edged Lankford in the district’s largest county, Oklahoma, but Lankford did better in the district’s other two counties, Pottawatomie and Seminole. Whoever wins will be the favorite over Democrat Billy Coyle and two independent candidates in November in this Republican-leaning district.

“It really comes down to, how big is your base?” explained Matt Pinnell, chairman of the Oklahoma Republican Party.

The second district will also have a runoff, but it’s unlikely to be consequential. Republicans Charles Thompson, who finished with 34 percent of the vote in July, and Daniel Edmonds, who finished with 28 percent, will face off for the right to oppose three-term Rep. Dan Boren. Boren, a Blue Dog and the only Democrat in Oklahoma’s Congressional delegation, won his first race in 2004 with 66 percent of the vote and hasn’t fallen below 70 percent since.

Only one statewide race is on Tuesday’s ballot in Oklahoma: Republicans John Crawford and John Doak will vie for the right to take on Democratic incumbent Kim Holland for insurance commissioner.