Still, Gingrich acknowledged that he was urging his biggest supporter — casino mogul Sheldon Adelson — to donate heavily to the Romney campaign. After giving more than $25 million to a super-PAC supporting Gingrich in the primaries, Adelson has now pledged $10 million to the outside group supporting Romney. Multiple reports say Adelson is prepared to spend upwards of $100 million during the 2012 campaign.
"Look, I've told my supporters, this is the most important election of our lifetime," Gingrich said. "Any conservative who sits on the sidelines is helping reelect Barack Obama, and I think an Obama second term, for our values, would be a nightmare."
The Romney super-PAC, Restore Our Future, is already putting that money to work, on Monday announcing a $7 million television campaign across eight battleground states.
The group will go up with ads in Colorado, Florida, Iowa, Nevada, New Hampshire, North Carolina, Ohio and Pennsylvania, according to a report in The Washington Post. The 10-day blitz will begin airing Wednesday.
Gingrich conducted the interview at the National Zoo in Washington, an appropriate setting after making detours to the nation's zoos a regular part of his primary campaign. As a candidate, Gingrich regularly tweeted recommendations about which exhibits and animals to see, and memorably was nipped on the finger by a penguin at the St. Louis zoo.
"Elephants are among my favorites, partly because I'm Republican and partly because I'm big. Elephants make me feel like I'm the right size," Gingrich told ABC News. "They're very smart animals."