While Liz Cheney’s challenge to Sen. Mike Enzi fits one model of conservative maneuvering to keep rightward pressure on the GOP–an effort to replace of relatively weak time-servers with loud-and-proud ideologues–another is about to be initiated in Kentucky with Matt Bevin’s primary challenge to Mitch McConnell. Bevin, a wealthy hedge-fund guy who has been scheming with Club for Growth and Senate Conservative Fund operatives, is expected to announce his challenge on Wednesday, and has already booked some ad time.

The primary appears likely to get off to a fast start, with McConnell’s campaign manager calling Bevin an “East Coast con man,” and one of Bevin’s “advisers” referring to the Senate Majority Leader as “Mud Slinging Mitch.”

The rather transparent motive of the national groups encouraging Bevin is to make sure McConnell doesn’t attempt any “moves to the center” in anticipation of a competitive general election fight against Democrat Alison Lundergan Grimes, Kentucky’s Secretary of State. They probably want to make sure Mitch understands that his apparent detente with his junior colleague Rand Paul–who smoked McConnell’s candidate in a 2012 primary–is not enough to give him a preemptive pass score on upcoming ideological litmus tests.

Another prominent Republican leader who may soon draw a 2014 challenger is Lindsay Graham, whose approval rating among South Carolina Republicans has been steadily dropping of late thanks to his high-profile involvement in the Gang of Eight group sponsoring immigration reform legislation. The latest name to be bruited about is that of Nancy Mace, famous as the first woman to graduate from The Citadel, who has been making the Tea Party rounds in the Palmetto State in anticipation of a possible run against Graham.

It’s not clear yet whether a challenge to Graham would be like one to McConnell–a shot across the bow aimed at influencing his behavior, with the perpetual possibility of things getting more serious if the incumbent makes a mistake–or the one to Enzi, which could be described as wolves circling a weak member of the flock. Either way, unless Graham dodges a serious GOP opponent altogether, we’ve probably pretty much seen the last of his “independent” ways in the Senate until after 2014.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.