The NRSC and Ross's campaign released TV ads Wednesday.
Bayh missed more than three-quarters of the hearings between 2003 and 2011, the report said.
The ad, which will run until Nov. 4, is part of a $900,000 ad buy.
Liberal firebrand Elizabeth Warren on Tuesday continued her onslaught against GOP lawmakers backing Donald Trump, calling Sen. Richard Burr (N.C.) a "puppy on a leash" for supporting the Republican presidential nominee.
Republicans are investing $25 million in six close Senate races as Election Day nears.
"It's a secret ballot," said Rep. Joe Heck (R-Nev.).
Rep. McCaul sidestepped a question about if he supports Cruz.
Gov. Maggie Hassan pivoted to Sen. Kelly Ayotte's previous support for Donald Trump.
Tim Devaney 10/25/16 02:30 PM EDT
North Carolina could prove essential to Democrats' plan to regain control of the Senate.
Rafael Bernal 10/25/16 02:22 PM EDT
His Democratic opponent's campaign sent out video of the boos.