Mitt Romney backs Mark Kirk for US Senate at Chicago stop

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CHICAGO (AP) — Former Republican presidential nominee Mitt Romney is in Chicago to support Illinois U.S. Sen. Mark Kirk's bid for a second term.

Kirk is facing a challenge from Democratic U.S. Rep. Tammy Duckworth in a race that will help determine whether Republicans keep control of the Senate.

Romney endorsed Kirk on Wednesday, calling the Republican an "independent voice" who's willing to work across party lines.

The former Massachusetts governor, who lost to President Barack Obama in 2012, also says the GOP must hold on to the Senate to "keep America from going off the rails."

Both Romney and Kirk have been vocal opponents of GOP nominee Donald Trump.

Democratic Party of Illinois spokesman Sean Savett says Romney's visit is an attempt to "bail out" Kirk's campaign.