The Republican race for president moved to New Hampshire Wednesday where former Massachusetts Gov. Mitt Romney—fresh off a razor-thin win in Iowa over former Pennsylvania Sen. Rick Santorum—picked up the endorsement of the Republican Party’s 2008 nominee, Sen. John McCain.

Mr. McCain (R., Ariz.) threw his support behind Mr. Romney at a campaign event in Manchester, N.H., after Mr. Romney eked out a razor-thin Iowa victory. “New Hampshire is the state that will catapult him on to victory,” Mr. McCain said of Mr. Romney. “That’s why I’m here.”