The Republican-affiliated Crossroads GPS is launching new ads in Iowa and Arkansas, attacking Rep. Bruce BraleyBruce BraleyTrump: Ernst wanted 'more seasoning' before entertaining VP offer Criminal sentencing bill tests McConnell-Grassley relationship Trump's VP list shrinks MORE (D-Iowa) on the Veterans Affairs Department and hitting Sen. Mark PryorMark PryorCotton pitches anti-Democrat message to SC delegation Ex-Sen. Kay Hagan joins lobby firm Top Democrats are no advocates for DC statehood MORE (D-Ark.) on Medicare and Social Security.

The Crossroads ad criticizes Braley for missing committee meetings overseeing the VA, an issue that has nagged his campaign.

"Veterans died waiting for care," the Iowa ad says. "But Congressman Braley actually missed 75 percent of full committee meetings as a member of the Veterans Affairs Committee."

The Arkansas spot goes after Pryor on Medicare, ObamaCare and Social Security, seemingly looking to muddy the issue after recent Democratic attacks on Rep. Tom CottonTom CottonKoch-backed group stepping up advocacy against border tax GOP senator: 'Serious concerns' about House border tax plan GOP senators to Trump: We support 'maintaining and expanding' Gitmo MORE's (R-Ark.) Medicare views.

The ad accuses of Pryor of talking about raising the Social Security retirement age and calls on him to "protect our Medicare by repealing ObamaCare."

Both races are top GOP priorities. Cotton and Pryor have been locked in a tight and nasty race for months, while Braley's missteps have put him in a coin-flip race against Iowa state Sen. Joni Ernst (R).

Braley's campaign fired back.

"It's shameful that Karl Rove is trying to play politics with our veterans and distort Bruce Braley’s impressive accomplishments for Iowa’s veterans," Iowa State Representative and Army Reserve Major Todd Prichard (D) said in a statement from the campaign.

This post was updated at 3:00 p.m.