Some senators can be hesitant about donating to the campaigns of challengers to the chamber's leaders.

Not so with GOP Whip Jon Kyl (Ariz.). He's among a handful of senior Republicans who plan to donate to the campaign of Tea Party favorite Sharron Angle — the Republican challenger to Majority Leader Harry Reid (D-Nev.).

Kyl told The Hill he has no trepidation about going after Reid. He endorsed and campaigned for Angle's opponent Sue Lowden in Nevada's Republican Senate primary. 

Asked if he plans to donate to Angle's campaign, Kyl pointed to former Democratic Senatorial Campaign Committee Chairman Charles Schumer's (N.Y.) financial support of former Arizona Democratic Party Chairman Jim Pederson during Kyl's re-election in 2006.

"I will support every Republican nominee financially in this coming election for the Senate," Kyl said. "I just ran for re-election in 2006, and my good friends on the Democratic side of the aisle had no trepidations about pouring a lot of money into my opponent's campaign."

Kyl said he got the last laugh, recalling a post-election conversation with Schumer.

"After the campaign, I was able to go to Sen. Schumer and say 'Why did you waste so much money?'"

In 2008, Minority Leader Mitch McConnell's (R-Ky.) was a Democratic target and several Democratic senators and senatorial candidates contributed to his Democratic challenger, Bruce Lunsford.

Those donors included: Reid, Hillary Rodham Clinton (N.Y.), Russ Feingold (Wis.), Sheldon Whitehouse (R.I.), Dick Durbin (Ill.), Barbara Boxer (Calif.), Ben Nelson (Neb.), Robert Menendez (N.J.), Jack Reed (R.I.), Blanche Lincoln (Ark.), Robert Casey (Pa.), Mark Warner (Va.), Amy Klobuchar (Minn.), Byron Dorgan (N.D.), John Kerry (Mass.), Jeff Bingaman (N.M.), and Sherrod Brown (Ohio).