Meet Rick Santorum: Everything You Need to Know (And Probably Didn’t) About the 2016 Republican Presidential Candidate

— -- Name: Richard John "Rick" Santorum

Party: Republican

What he does now: After leaving Congress in 2007, Santorum took a job as a consultant at a conservative think tank in Washington, became a Fox News contributor and joined a law practice in Pittsburgh. In addition to unsuccessfully running for president in 2012, he's also authored several books, including one about his daughter, and runs a small Christian movie studio.

What he used to do: Santorum, 57, served as a U.S. senator from Pennsylvania from 1995 to 2007, and as a U.S. congressman representing his home state for four years before that. He became the third highest-ranking Republican in the Senate in 2001, when he was elected chairman of the Senate Republican Conference, a position he held for six years. He ran for president in 2012, winning primaries and caucuses in 11 states before losing the Republican nomination to Mitt Romney.

Declared as a candidate: May 27, 2015, in Cabot, Pennsylvania.

In his own words: "I'll offer a bold vision for America, one that is clear and conservative that has plans for reform and a proven track record from my time in service."

What you might not know about him: The second of three children born to a nurse and a psychologist, Santorum’s Catholic upbringing influenced his beliefs later in life. He was born in 1958 in Winchester, Virginia, but grew up mainly outside Pittsburgh. Both of his parents worked for the Veterans Administration, and he lived at the veterans’ hospitals -- “I always joked that I spent my childhood living in public housing,” he said in 2011. Santorum went on to get undergraduate and law degrees from Penn State and an M.B.A. from the University of Pittsburgh.

How he'll approach the election this time: Santorum finished second to Romney in the race for the Republican presidential nomination in 2012, but he said in December he thought a presidential run in 2016 would be an uphill battle. "America loves an underdog. We’re definitely the underdog in this race," he told The Washington Post then. He said he learned from last time and is trying to broaden his appeal: "I get the game," he said.

He practices what he preaches: Santorum and his wife, Karen, have seven children, and they've home-schooled them all. During his first presidential campaign, he ran an ad trumpeting that fact -- but made clear their home-schooling philosophy did not extend to the family dog.

His daughter wasn't expected to live past her first birthday: Santorum's youngest daughter, Bella, was born in 2008 with a rare disorder called Trisomy 18, which takes the life of almost all children born with it before they turn one year old. During his 2012 campaign, he and his family kept her out of the public eye while they struggled with her care -- until the Republican National Convention that year, where he spoke of Bella being "full of life" despite doctors' earlier misgivings. In 2015, he and his wife authored a book titled, "Bella's Gift: How One Little Girl Transformed Our Family And Inspired A Nation."

He once gave his sweater vest to Jay Leno: Santorum’s ubiquitous sweater vests became his unofficial campaign uniform when he ran for president in 2012, inspiring their own jokes and social media accounts. He embraced the outfit with a slew of colors, sold $100 versions on his campaign website and has gifted them to the likes of Jay Leno and Stephen Colbert.