(CNN) - National Republicans are doubling down on contentious Senate races in Colorado and Kentucky Wednesday with new ads seeking to undermine the all-ready embattled Democratic candidates.
In the new spot hitting Colorado airwaves, the National Republican Senatorial Committee accuses incumbent Sen. Michael Bennet of championing his party's "reckless spending policies" and "more concerned about supporting President Obama's priorities than representing Coloradans' best interests in Washington."
"Michael Bennet cast the deciding vote for Obama's stimulus, that wasted billions, added to the debt, and didn't create the jobs they promised," the ad states.
In Kentucky, the new NRSC ad accuses Democratic candidate Jack Conway of flip-flopping on whether he thinks the Bush tax cuts should be extended.
"Hey, Jack…waffles are for breakfast…not for Senators," that ad states.
Conway is neck-and-neck with Republican Rand Paul according to several recent polls while, in Colorado, Bennet finds himself several points behind Republican Ken Buck.