Sen. Jon Tester, D-Mont., faces a potentially tough re-election bid. Win McNamee/Getty Images hide caption

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Former Massachusetts Gov. Mitt Romney gives a victory speech Tuesday in Novi, Mich., after winning the state's primary. Gerald Herbert/AP hide caption

itoggle caption Gerald Herbert/AP

A line of people wait outside the 11th U.S. Circuit Court of Appeals, which heard arguments over tough new laws targeting illegal immigration in Alabama and Georgia on Thursday. John Amis/AP hide caption

itoggle caption John Amis/AP

Students hoping for a repeal of California's ban on affirmative action in college admissions protest outside of the 9th U.S. Circuit Court of Appeals in San Francisco on Feb. 13. The Supreme Court will decide an affirmative action case next fall that could affect college admissions policies across the country. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Honda has a huge presence in Ohio, where the company and its suppliers are hiring. Here two advanced continuously variable transmissions undergo leak testing at the new assembly line at the Honda plant in Russells Point, Ohio. Ron Lietzke/AP hide caption

itoggle caption Ron Lietzke/AP