During a GOP debate on Sunday, former House Speaker Newt Gingrich told Mitt Romney to "drop the pious baloney" after the former Massachusetts governor asserted that for him, "politics is not a career."

"I think it's understandable and perhaps unusual that people who spend their life in politics imagine that if you get in politics that that's all you want to do," Romney said defending his decision not run for re-election as Massachusetts governor. "I went to Massachusetts to make a difference. I didn't go there to begin a political career, running time and time again. I made a difference, I put in place the things I wanted to do."

"Are you going to tell people you're not going to run for re-election for president if you win?" former Pennsylvania Rick Santorum interrupted.

"This for me, politics is not a career," Romney, who began running for office in 1994, replied. "For me, my career was being in business. ... I long for a day when, instead of having people who go to Washington for 20 and 30 years, who get elected and then when they lose office, they stay there and they make money as lobbyists or connecting to businesses. I think it stinks."

NBC debate moderator David Gregory gave Gingrich a chance to respond.

"Look, can we drop a little bit of the pious boloney?" Gingrich quipped. "The fact is, you ran in 94 and lost. That's why you weren't serving in the Senate with Rick Santorum. The fact is you had a very bad re-election rating. You dropped out of office. You had been out of state for something like 200 days preparing to run for president. You didn't have this interlude of citizenship while you thought about what to do. You were running for president while you were governor."

"You then promptly re-entered politics," he added. "You happened to lose to [Arizona Sen. John McCain] as you had lost to [former Massachusetts Sen. Edward Kennedy]. Now, you're back running. You've been running consistently for years and years and years and years. So, this idea that suddenly citizenship showed up in your mind, just level with the American people. You've been running for at least since the 1990s."

"I happen to see my dad run for governor when he was 54 years old," Romney replied. "He said, 'Mitt, never get involved in politics if you have to win election to pay a mortgage.'"

"I never thought I'd get involved in politics," the former Massachusetts governor continued. "When I saw Ted Kennedy running virtually unopposed in 1994 -- a man who I thought by the virtue of the liberal welfare state had created a permanent underclass in America -- I said someone's got to run against him. ... I was happy that he had to take a mortgage out on his house to ultimately defeat me."

Watch this video from MSNBC, uploaded Jan. 8, 2012.