A series of instances in which Democratic candidates have belittled their opponents’ military service is prompting a push-back from veterans groups and Republicans who note that the attacks are coming from career politicians who never served in the armed forces.

In the most high-profile instance, embattled Arkansas Sen. Mark Pryor (D) said his GOP opponent, Rep. Tom Cotton, has a “sense of entitlement that he gives off is that almost as like ‘I served my country, therefore elect me to the Senate. That’s not how it works in Arkansas.”

Cotton is now running ads hitting back that feature his former drill sergeant putting him through the paces while delivering a humorous rebuttal.

“Drill Sergeant Norton taught me how to be a soldier,” Cotton says in the ad. “Accountability, humility, and putting the unit before yourself. That training stuck.”

“It better have!” Sergeant Norton replies.

In another instance, this one featuring a Democrat-on-Democrat attack, Maryland Attorney General Douglas Gansler scoffed that his opponent Lt. Governor Anthony Brown service in Iraq wasn’t a “real job” in an aside on Obamacare during a public event.

“You know, I’m running against somebody who has never managed anybody, never run anything. You know his ads are about how he was a lawyer in Iraq, and that’s all fine and good but this is a real job,” Gansler said at a candidate forum Monday in Bethesda, Maryland.

VoteVets.org, a political action committee that donates to Democratic candidates and has backed Brown in the Maryland primary, ripped Gansler and demanded he apologize, calling the remarks a “a horrible insult to all those men and women who put their lives on the line.”

Gansler refused to apologize but did offer a “clarification” that he respects Brown’s military service, even while lambasting his record in the next sentence of the statement.

In a third instance, Alaska Sen. Mark Begich (D) is attacking a Republican challenger, former Marine Dan Sullivan, for leaving Alaska following the September 11, 2001 terrorist attacks to work at the White House on national security issues. For two years during his stint in Washington, D.C., Sullivan was recalled to active military duty.

An ad from the National Republican Senatorial Committee features a local newscaster asking “Really? You’re going to begrudge the guy for that? I don’t think so.”

Veterans who served alongside Sullivan have also ripped the attacks.

Begich’s campaign website features a page questioning how authentic of an Alaskan Sullivan is, noting he owns a home in Maryland from his time working at the White House.

Neither Pryor nor Begich served in the military. Pryor’s father was a senator, while Begich’s father was a representative.