The arguments have gotten so pointed that Senate Republican Conference Chairman Lamar Alexander (R-Tenn.) wore a flak jacket to a Republican lunch meeting a few weeks ago.

He said he would don the protective gear after Rep. Tom Coburn (R-Okla.), an outspoken conservative, blasted him in a meeting for arguing that Congress had already made substantial reductions in discretionary spending…

Alexander, a member of the Appropriations Committee, made a presentation to the conference highlighting cuts Congress has already made to discretionary spending…

Coburn objected heatedly. He argued that slowing the rate of discretionary spending growth is not the same as cutting spending, according to sources. Senate aides say that conservatives including Sens. Mike Lee (R-Utah), Rand Paul (R-Ky.) and Ron Johnson (R-Wis.) agree with Coburn’s point of view.