The gun control group founded by Gabby Giffords and her husband, Mark Kelly, has endorsed two Republican Senators in tough re-election fights as it seeks to expand its outreach.

In an op-ed on CNN Monday, Americans for Responsible Solutions backed Sens. Pat Toomey of Pennsylvania and Mark Kirk of Illinois, who are both facing tough re-election races in a year in which Democrats hope to regain control of the Senate.

The two sitting Senators voted in favor of gun control proposals after the Sandy Hook Elementary School shooting, where 20 children were killed.

“In the wake of the tragedy at Sandy Hook, Republican Sens. Pat Toomey and Mark Kirk 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,” wrote Giffords and Kelly in the op-ed.

It is unusual for a gun control group to support Republicans. Americans for Responsible Solutions is usually more aligned with Democrats sympathetic to expanding background checks and passing gun safety laws. But the group is seeking to appeal to both sides of the political spectrum, arguing its proposed legislation is supported widely as polls show some 9 in 10 Americans favor universal background checks.

“With the vocal majority of Americans behind us, our movement has reached a tipping point. Our coalition is black and white, Latino and Asian. We are gay and straight. We are gun owners. We are Democrats and Republicans,” said Giffords and Kelly in the op-ed.

Toomey is slightly trailing Democratic candidate Katie McGinty in his Pennsylvania race and Kirk is facing a tough challenge from Rep. Tammy Duckworth. Kirk has disavowed Donald Trump, the Republican nominee.

Along with Sens. Susan Collins of Maine and John McCain of Arizona, Toomey and Kirk were the only four Republicans to vote for a bipartisan compromise on a gun control bill after Sandy Hook known as Manchin-Toomey that would have expanded background checks on private gun sales. The amendment, which needed 60 votes to pass, failed 54-46.

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