Former U.S. Senator Rick Santorum launched his second campaign for the White House on Wednesday. He joins a crowded group seeking the 2016 Republican presidential nomination.

Mr. Santorum made the announcement at a manufacturing plant in Pennsylvania. He represented the state in both the House and the Senate from 1991 until 2007.

In his first presidential campaign in 2012, Mr. Santorum surprised people with an early win in the Iowa caucus. He won 10 more state caucuses and primaries before losing to Mitt Romney, the party's nominee.