The air wars have already begun in Arkansas.

Republican Rep. Tom Cotton, who is challenging Democratic incumbent Sen. Mark Pryor in next year's election, ran his first-of-the-campaign attack ad, charging that Pryor supports the unpopular Obamacare program because Pryor voted for government bills that included funding for the health care law.

"Mark Pryor cast the deciding vote to make you live under Obamacare," Cotton's ad says. "But Pryor votes himself, and everyone in Congress, special subsidies so they're protected from Obamacare."

A day later, Pryor responded with an ad of his own, charging that Cotton was inappropriately focusing on politics during a government crisis and claiming Cotton missed House votes during the government shutdown.

"Tom Cotton: just reckless and irresponsible," Pryor's ad says.

Pryor is widely seen as the most vulnerable Democratic incumbent up for election next year, and the Republican bid to unseat him is expected to make the race one of the nation's most contentious and expensive.

Conservative groups, meanwhile, are already running their own ads in Arkansas. The Club for Growth, which endorsed Cotton, is running a six-figure ad buy attacking Pryor.



Wisconsin Democrats have found a challenger for Republican Gov. Scott Walker in next year's election.

Mary Burke, a former executive for Trek Bicycle Corp. and daughter of the company's founder, said she's going to run. The state party has been wooing Burke for months, hoping her business background would help draw voter attention to Walker's failure to create as many jobs he promised.

"Helping to turn my family's business into a global company has been a big part of my life," Burke said in an online video announcing her candidacy. "Now I'd like to help make our great state of Wisconsin even better as your governor."

Walker infuriated Democrats by curbing the bargaining power of public employee unions and they pushed for a recall election in hopes of ousting him before his first term was up. But Walker won the recall and is seeking a second term in the traditionally Democratic state.



Republican Sen. John Cornyn doesn't have a serious challenger yet in his 2014 bid for re-election. But he's taking no chances.

The Texas Republican ended July with nearly $6 million in his campaign war chest, and he is spending several hundred thousand of those dollars on a statewide television ad touting his conservative credentials.

"Our John Cornyn," the ad's narrator says. "Conservative like you, like Texas."

The most serious threat to Cornyn's re-election isn't from Democrats. His greatest worry is a primary challenge from another Texas Republican who will attack him from the right, someone more like his conservative senate colleague, Ted Cruz.

Cornyn remained relatively silent during the Republican push to defund Obamacare, a push led by Cruz. Though it resulted in a government shutdown, the defunding strategy fired up the Tea Party wing of the GOP, and conservative groups are increasingly challenging Republican incumbents they consider too moderate.