Long ago, Rush Limbaugh dubbed him “Lindsey Grahamnesty.”

Last week, Glenn Beck branded him “one evil guy.”

On a seemingly daily basis, purportedly conservative critics denounce him as a “RINO” (Republican In Name Only).

And on Monday, WTMA radio’s Tara Servatius read an email from a listener who called our senior senator — brace yourselves, sensitive readers — “a Democrat.”

Their most heated recent case against Lindsey Graham:

As a member of the Senate “Gang of Eight,” he’s pushing an immigration reform bill that they deem lacking on border security.

The perils of cooperation

But if you think that thunder on the rigid right is heavy, ponder what the liberal Huffington Post labeled our extraordinarily liberal president when the National Security Agency snooping scoop broke 12 days ago:

“George W. Obama.”

That moniker was accompanied by a photo combining the facial images of our last two presidents.

Clearly, too many on the loony left still regard George W. Bush as “one evil guy.”

No wonder our elected officials can’t reach common ground.

Perceived deviations from ideological orthodoxy risk excommunication from the two major parties.

Gerrymandering, while protecting those parties’ death grips on “safe seats,” forces Republicans to run to the hard right and Democrats to the hard left in primaries.

That leaves a long road to politically possible compromise, which has become a dirty word for zealots on both sides.

Some overwrought liberals even brand Obama as too moderate, despite his fixation on big-government remedies to ailments induced by big government.

Some overwrought conservatives even brand Graham too moderate, despite his well-chosen fixation on exposing the Obama administration’s Benghazi blunders and deceit — and his admirable No. 5 Senate ranking, by the National Taxpayers Union Foundation, in proposing and sponsoring spending cuts in 2011 and 2012. (Jim DeMint, who quit on the job on us late last year, was No. 3.)

Searching for a center

The last Democrat to win a statewide race in South Carolina wants to offer a third way — a middle way — with the new American Party.

Jim Rex, who edged Republican Karen Floyd in the 2006 state education superintendent’s race by just 455 out of nearly 1.1 million votes cast, came to this newspaper last week to pitch that “positive disrupter” alternative.

Rex, who didn’t run for a second superintendent’s term and finished a distant second to state Sen. Vincent Sheheen in the 2010 Democratic gubernatorial primary, said he has no interest in seeking office again.

Yet the man who has been frequently called — brace yourselves again — an “educrat” is trying to get this party started in this state.

Rex said folks in several other states are creating American Party chapters of their own.

Along with Dr. Oscar Lovelace, a far-away second to then-Gov. Mark Sanford in the 2006 GOP primary, Rex has launched a petition drive to certify the party in this state.

Rex conceded that the party has only “an outside chance, because there is no inside chance.”

Still, a middle-road option sounds inviting — especially after hearing Beck, a sanctimonious, self-proclaimed “seer” who wields ominously ample influence over some GOP lawmakers, call Florida Sen. Marco Rubio a “dirt bag” last week.

Sure, many problems are extreme enough to defy middling solutions.

But at least if you ran as an American Party candidate, nobody could call you a “RINO” — or a “DINO.”

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