(CNN) - Rep. Steve King hasn't even declared whether or not he will run for the U.S. Senate.
But on Thursday the Iowa Republican sent a plea to supporters charging veteran GOP strategist Karl Rove was marshalling forces against him in a preemptive effort to push him out of the race.
"Karl Rove and his army have launched a crusade against me," he wrote in an email published online by the Des Moines Register.
King's email brings to the fore intra-party GOP bickering. On one end, the GOP establishment represented in this instance by Rove. On the other, the tea party, represented here by King.
The congressman is known as a staunch conservative and was identified as a target of the Conservative Victory Project - a name at which some conservatives scoff - in a recent New York Times interview with the group's leader, Steven Law. The project is an offshoot of Rove's super PAC American Crossroads, which backed various Republican bids for federal office in the 2012 election.
But that election also saw GOP losses in races where a conservative candidate made statements on controversial topics, such as Missouri Rep. Todd Akin's race for the U.S. Senate which derailed after his comments on "legitimate rape."
"We're concerned about Steve King's Todd Akin problem," Law told the Times. "This is an example of candidate discipline and how it would play in a general election. All of the things he's said are going to be hung around his neck."
Jonathan Collegio, the communications director for American Crossroads, underscored that point in an interview with CNN: "The idea is if we have a shot to win a seat we don't want a candidate like Christine O'Donnell or a Todd Akin to destroy that effort.
"We have an opportunity to take back the Senate and the House, or to hold the House, this cycle, and we want to make sure we are getting the best candidates available," he said.
King's email makes his point just as bluntly: he is not the problem.
"Nobody can bully me out of running for the U.S. Senate, not even Karl Rove and his hefty war chest," he wrote, according to the Register.
He told Radio Iowa later in the day that he has not yet made a decision, and when it does it will be based on "a thorough analysis." “It’s gotten closer each day, but I wouldn’t want to imply that the decision is made. It’s not,” he said.
He specifically cited in his email the Times report and described the Conservative Victory Project effort as "outlandish."
Law specifically cited King in the interview with the Times as an example of candidates they would target.
But asked by CNN if his group would continue going after him, Collegio demurred.
"This could be a test case. We don't know yet," he said. "It is too early to say what the field is going to look like in Iowa or any other state."
The Senate seat is being vacated as long-time Democratic Sen. Tom Harkin plans not to seek a sixth term in 2014. In his statement announcing the decisions, he said "I just feel it's somebody else's turn" to represent the state.
Several potential candidates are mulling a bid for the seat. The only announced candidate so far is Democratic Rep. Bruce Braley.
– CNN's Gregory Wallace, Paul Steinhauser, Ashley Killough and Jim Acosta contributed to this report