U.S. Senator Mark Kirk has gained an endorsement in his bid for re-election. It could help him win crucial votes from suburban moderates, but it might also frustrate an important part of the Republican electorate.
Kirk is thought to be 2016's most endangered Republican senator.
Which is why his endorsement by former Democratic Congresswoman Gabby Giffords' anti-gun violence PAC could prove significant.
Giffords became a national figure in the fight for gun control following an assassination attempt in 2011.
In a just-published op-ed, Giffords and her husband, astronaut Mark Kelly, write that Kirk earned the endorsement of their Americans for Responsible Solutions organization because he "broke from the gun lobby and supported a bill to help prevent felons, domestic abusers and the dangerously mentally ill from obtaining firearms at gun shows and online."
But Giffords is also giving a nod to Kirk's opponent, calling Democratic Congresswoman Tammy Duckworth an "American hero" and "champion for commonsense gun laws."
Kirk's endorsement comes as he's under attack from Democrats for saying President Barack Obama acted like the "drug dealer in chief" in reference to payments America made to Iran. Democrats call the comment "ugly" and racially tinged.