By most accounts, Republicans running for Congress will have a good year. But those aiming for the governor's mansion? Not so much.

Late summer polling suggests Republican governors seeking re-election not only won't ride a GOP wave to victory, they may even be crushed.

As with Congress, the reasons are partly structural. Republican gubernatorial candidates did well in 2010 as part of the midterm backlash against President Obama.

Now, four years later, voters in many of those states are rebelling against their agenda.

In Kansas, Gov. Sam Brownback, who is seeking a second term, is trailing his Democratic opponent Paul Davis by about 3 points in the latest polling average compiled by RealClearPolitics. In Georgia, Gov. Nathan Deal is in a tossup race against Jason Carter, grandson of the former president.

The polling is even more ominous for Republicans in Pennsylvania, where incumbent GOP Gov. Tom Corbett is nearly 17 points behind Democrat Tom Wolf in the RCP polling average.

Overall, seven GOP governors could easily lose second-term bids to Democrats. In addition to Brownback, Deal and Corbett, Republican governors in Florida, Maine, Michigan and Wisconsin are in tossup races with tough Democratic opponents.

Meantime, Democratic incumbents are in a stronger position. Only four Democratic governors are at serious risk of losing to Republicans, and three of them are in blue states with a stronger base of Democratic voters.

Pollsters say state-level politics are working against the endangered GOP governors, many of them first elected in states that are not solidly Republican.

“Except for Brownback and Deal, these governors were elected in a Republican wave election from states Obama carried twice, so they have large, built-in opposition constituencies,” Ronald Faucheux, president of Clarus Research Group, told the Washington Examiner. “In some cases, most of these governors had to make tough decisions on fiscal issues that angered entrenched constituencies.”

The pattern is not holding in House and Senate races. Republicans are expected to pick up about five seats in the House and potentially six seats in the Senate, which would give them a majority in that chamber.

“What's hurting Democrats is Obama, and he's a bigger negative factor for them in federal elections than in state elections,” Faucheux said.

In Kansas, where voters have elected both Democratic and GOP governors, Brownback lost popularity after implementing budget reductions that included cuts to education.

“Democrats have really done a good job of painting Brownback’s education cuts in a negative light,” one Kansas GOP political strategist told the Examiner.

In Michigan, opponents of Republican Gov. Rick Snyder say he slashed school and government spending in exchange for tax cuts. He is now tied with Democratic opponent Mark Schauer.

But Snyder’s popularity suffered the most when he pushed for passage of a right-to-work law in 2012. The law makes it illegal to require employees to be forced to pay union dues.

“He signed the right-to-work law and his popularity dropped like a stone,” Lansing, Mich., pollster Bernie Porn, of Epic MRA, told the Examiner.

In a few campaigns, as always, there are some problems with the candidates themselves.

In Maine, Republican Gov. Paul LePage has earned a national reputation as an eccentric, sometimes off-the-rails chief executive, who once told the NAACP to “kiss my butt” and likened the IRS to the Gestapo.

LePage is tied in polls with Democrat Mike Michaud.

It’s not all bad news for Republicans. They are tied or ahead in races against Democratic incumbent governors in Illinois, Arkansas, Connecticut and Hawaii, where a primary knocked out Gov. Neil Abercrombie.

“I think there is an anti-incumbent mood out there,” Atlanta political strategist Todd Rehm said.