Republican Kansas Sens. Pat RobertsCharles (Pat) Patrick RobertsGOP senators eager for Romney to join them Canada tamps down worries about US NAFTA withdrawal Canada worried Trump will withdraw from NAFTA: report MORE and Jerry MoranGerald (Jerry) MoranDoug Jones to become only Dem senator with black chief of staff Congress should stand for rural America by enhancing broadband connectivity Immigrant entrepreneurs are vital to American prosperity MORE defended the Koch brothers Thursday after Senate Majority Leader Harry ReidHarry Mason ReidDems search for winning playbook Dems face hard choice for State of the Union response The Memo: Immigration battle tests activists’ muscle MORE’s (D-Nev.) called the pair “un-American” a day earlier.

“Yesterday two prominent citizens were called unpatriotic,” Roberts said Thursday. “Nothing David and Charles Koch have done is illegal.”

On Wednesday, Reid accused David and Charles Koch of running anti-ObamaCare ads that lie.

“I guess if you make that much money, you can make these immoral decisions,” Reid said on the Senate floor. “The Koch brothers are about as un-American as anyone I can imagine.”

Moran compared Reid to Joseph McCarthy, who used his congressional power to label people as communists in the 1950s.

“It’s troubling that there is a reflexive reaction in Congress to label people who disagree with you as un-American,” Moran said. “This tactic didn’t end in 1950 and indeed it continues today.”

The Koch brothers, who have made their fortune off U.S. oil, are from Kansas.

Reid also accused the brothers of trying to buy America. The Kochs sponsor several Tea Party and Republican groups that run political ads.