The GOP is going after Senator Harry Reid this Sunday:

Republican National Committee chair Reince Priebus called Sen. Harry Reid a “dirty liar” this morning on “This Week” for accusing presumptive GOP presidential nominee Mitt Romney of not paying taxes.

Reid, the Democratic Senate Majority Leader from Nevada, said in an interview with the Huffington Post last month that, according to a source that called his office, Mitt Romney did not pay taxes for ten years.

Meanwhile South Carolina Senator Lindsey Graham left off the 'dirty,' and just called him a liar:

Senator Lindsey Graham. R-S.C., called Senate Majority Leader Harry Reid, D-Nev., a liar on Sunday for comments Reid has made about Mitt Romney's taxes.

"I think he's lying about his statement of knowing something about Romney," Graham said on CNN's State of the Union.