Either Marlon Kimpson or Maurice Washington will win today’s S.C. Senate District 42 Democratic runoff.

Then, barring a major upset, the victor will win the Oct. 1 general election.

No offense to Republican nominee Billy Shuman and Libertarian nominee Alex Thornton. It’s just that District 42, as drawn, remains heavily Democratic territory.

And gerrymandering remains a voter “de-motivator.”

Of course, stacking the electoral deck by drawing districts along party lines isn’t new.

But this rigged game has intensified lately, due in part to technological advances in tracking voting patterns.

Robert Ford held the District 42 seat for more than 20 years before serious ethics charges forced his resignation in late May, and forced the special election to replace him.

How firm was Ford’s — and the Democrats’ — hold on that Senate seat?

He rolled to a nearly 2-to-1 landslide over an up-and-coming Republican Charleston County councilman in 1996. The victim of that ballot-box rout is now a U.S. senator — Tim Scott.

And we’re all victims of an incumbent (or at least party) protection racket that doesn’t merely lower general-election suspense. It lowers the probability of political compromise.

Unless, of course, the compromise involves divvying up safe seats for each party.

And that’s no joke

OK, so Democrat Elizabeth Colbert Busch gave Republican Mark Sanford a scare this year when he decided to run for his old seat in the GOP’s supposedly safe 1st Congressional District. But Sanford, despite still being a national “Appalachian Trail” punch line, prevailed by a 54 to 45 percent margin as the GOP maintained its 1st District grip that began with Tommy Hartnett’s election in 1980.

And the 6th District has remained solidly in Democrat Jim Clyburn’s hands, with no significant opposition from either party, since he won the seat in 1992 to become our state’s first black congressman since the 19th century.

Then again, Republican Scott is also black — and won the mostly white 1st District seat in 2010. Scott then became a U.S. senator at the start of this year, appointed by Gov. Nikki Haley to replace Jim DeMint, who quit on us with four years left in his second term to become the very-well-paid president of the Heritage Foundation.

Scott looks like a sure thing to keep that Senate seat when he runs for it next year.

However, Sen. Lindsey Graham already has three announced primary challengers from the right in 2014.

How far right?

Two weeks ago, one of them, state Sen. Lee Bright of Spartanburg, called Graham “a community organizer for the Muslim Brotherhood.”

Our senior senator will be called other bad names tonight, from 6 to 7:30 at North Charleston City Hall, as “Lowcountry conservatives” and Washington-based FreedomWorks hold a “Lindsey Graham Town Hall,” moderated by WTMA-AM 1250 morning-show host Tara Servatius. Graham, who really is a proven conservative despite the overwrought charges of some right-wing critics, isn’t expected to show up.

As GOP candidates are pushed farther right and Democrats farther left, politicians from both parties face a longer trip to the middle ground after being elected. And yes, that trend extends beyond gerrymandered districts.

Bridges to the future?

Sure, many of our most dire problems can’t be solved via compromise.

For instance, on the national level, repeatedly raising the federal debt ceiling in return for vague promises of eventual frugality will never save us from drowning in red ink.

Yet on the state level, before South Carolina’s decaying bridges start falling down, somebody somehow must pay for a way-overdue boost in road funding.

Back to our deep national divide: In each of the last four presidential elections, 22 states have gone for the GOP candidate and 18 for the Democrat. (South Carolina has backed the Republican in the last nine White House races.)

No wonder the 10 up-for-grabs states dominated the 2000-2012 presidential nominees’ attentions.

No wonder so few politicians venture away from their bases toward common ground.

No wonder so many Americans find the system so polarized that they’ve checked out of politics.

Still, we ultimately get the elected officials we choose — and thus deserve. So vote for the candidates of your choice, if not today then the next time you get a chance.

Just don’t count on beating the gerrymandering odds anytime soon.

Frank Wooten is assistant editor of The Post and Courier. His email is wooten@postandcourier.com.