Newt Gingrich, the colorful former House speaker and fiery partisan, formally exited the Republican presidential contest Wednesday and vowed to help Mitt Romney’s bid to defeat President Barack Obama.

Ending a campaign that seesawed between implosion and frontrunner and back again, Gingrich threw his support to his one-time rival as expected and promised his supporters he would continue to push conservative ideas. Gingrich bowed out of the race more than $4 million in debt and his reputation perhaps damaged.

“Today, I am suspending the campaign. But suspending the campaign does not mean suspending citizenship,” Gingrich told a ballroom in a suburban Washington hotel.

“We are now going to put down the role of candidate and candidate’s spouse and take back the role of active citizens,” he said, adding he would continue to promote conservative ideas on college campuses, as well as through newsletters and films.

He also urged conservatives to rally behind Romney as a better alternative than Obama.