Oklahoma and South Carolina don’t top the list for most competitive gubernatorial races in 2018, but Democrats hope to reach for both governor’s mansions this year anyway — especially if Republicans nominate unpopular incumbent and incumbent-tied candidates Tuesday.

The story here isn’t necessarily about President Trump.

Republicans may be victims of their own success in governor’s mansions. They hold a near-record-high number of them: 33 of 50. In states such as Oklahoma and South Carolina, the very fact they're in power could be hurting them.

Voters in both states with elections Tuesday are incredibly unhappy with their current governors. Some of that discontent is personality-driven, such as in South Carolina, where Gov. Henry McMaster (R) is having trouble unpinning the label his opponents slapped on him as a corrupt insider. His runoff against businessman John Warren on Tuesday is expected to be close, even after Trump goes there Monday night to campaign for McMaster.

McMaster, having witnessed a few weeks ago how much a tweet from Trump can reverberate in his state, personally lobbied for Trump to come campaign for him. But people watching that race say some conservative voters have an aversion to McMaster that could make him a weakened general election candidate.

In Oklahoma, Republicans’ troubles are more policy-driven. Term-limited Gov. Mary Fallin (R) and the Republican-controlled legislature are taking heat from conservatives for approving tens of millions in taxes this spring to lift teacher pay and school funding.

But an energized left and middle are frustrated that Republicans didn't raise teacher pay enough. Even in a heavily Republican state, that bloc could be enough to make an electoral difference. Oklahoma ranks among the states with the lowest teacher pay, and many of its teachers went on a nine-day walkout in April.

The mixed political reaction to that strike has put Republican candidates trying to replace Fallin in an uncomfortable spot: Do they stick with traditional Republican orthodoxy and disapprove of the tax increases? Or do they support the tax hikes that their own party approved?

Lt. Gov. Todd Lamb has decided to oppose the tax hikes, even though he is part of the administration that signed off on them. He actually left Fallin’s Cabinet last year to try to separate himself from his boss, as Fallin’s popularity took a nose-dive as she considered other tax increases to fill a $900 million budget shortfall.

Lamb is the best-known name in the 10-person Republican gubernatorial primary. But because of his ties to the governor, he may be the weakest in a general election. Republicans in Washington say they’ll likely have to spend money in the general election to boost Lamb over a Democrat. That’s no small thing, given that the state voted for Trump by more than 35 points and Trump is still liked by about 55 percent of the state.

Oklahoma Lt. Gov. Todd Lamb (R). (Sue Ogrocki/AP)

Republican polls suggest that a more promising general election candidate for them is former Oklahoma City Mayor Mick Cornett. Democrats acknowledge that he could be tough to tackle, since he’s harder to pin Fallin's unpopularity to.

Another candidate trying to take advantage of anti-incumbency sentiment is Kevin Stitt, a mortgage company owner who was the least known in the Republican field when he entered the race but has spent more than $1 million of his own money to change that.

If no candidate gets a majority of the vote Tuesday, the top two will go to a runoff in late August.

That's a likely scenario, and it means Democrats could have another advantage in Oklahoma’s governor’s race: a head start campaigning. Former Oklahoma attorney general Drew Edmondson is expected to win Democrats’ gubernatorial primary outright Tuesday.

He’ll try to reactivate what Democrats in Washington describe as a “siren call” of liberal voter enthusiasm in the Trump era, which has manifested in Oklahoma during the teacher walkouts and several remarkable state legislative wins for Democrats.

In November, Democrats won a state legislative seat in a district that voted for Trump by nearly 40 points. That’s just one of four state legislative seats in Oklahoma they’ve flipped so far, which makes the state one of the first Democrats point to when highlighting their side’s enthusiasm.

Democrats also feel pretty good about their candidates for governor in other red states. Stacey Abrams, the nominee in Georgia’s open governor's race, is one of their star recruits of 2018, though some question if she’s too far left to win the state.

In South Carolina, Democrats nominated a veteran and Purple Heart recipient, state Rep. James Smith, who’s been able to campaign while McMaster has been focused for the past few weeks on his runoff.

While Republicans acknowledge that all these races in traditionally red states could be potentially competitive, they think (and hope) that Democrats have made missteps in who they chose. Specifically, by nominating candidates who aren’t as socially or fiscally conservative as the rest of the states.

“Democrats can nominate the best person they’ve got, but if they are a pro-choice and pro-tax-increase candidate in a deep-red state, they’ve got an uphill battle,” said Jon Thompson, spokesman for the Republican Governors Association.

Still, Democrats have reason to be optimistic — even bordering overly optimistic — in these states thanks to unpopular Republican leadership and a swell of Democratic voter enthusiasm that's flipping state legislative seats deep in Trump country already.