(CNN) -- After taking heat over his lukewarm endorsement of Mitt Romney, Newt Gingrich ramped up his support for the presumptive GOP presidential nominee Sunday.
"I believe that Mitt Romney will be a dramatically better president than Barack Obama," Gingrich said on CNN's "State of the Union.' "I believe he has earned the right to represent the Republican Party, and he has earned it the hard way."
Gingrich suspended his campaign Wednesday, offering mild praise for his former Republican primary opponent and saying Romney was only conservative compared to President Barack Obama.
On Sunday, six months before the November 6 election, Gingrich said he has already been in talks with Romney's campaign to appear at "several major events."
"I've said to the campaign I will be available at their convenience and do whatever they want me to do because they're in charge. This is their campaign," Gingrich told CNN Chief Political Correspondent Candy Crowley. "I've got to be there as an associate, but I'm not the leader. Mitt Romney is the leader."
Asked if he was expecting a prime speaking role at the Republican National Convention in August, Gingrich said he would be open to such a proposal.
"If they think I'm helpful speaking at the convention, I'm glad to do it," Gingrich said, though adding he's not in dire need of the airtime. "I can get on TV fairly often with or without a speech at the convention."
Weighing in on Tuesday's big Republican primary for Indiana's U.S. Senate race, Gingrich said he expects State Treasurer Richard Mourdock to beat six-term incumbent Sen. Dick Lugar.
Backed by tea party support and endorsements from high-profile conservatives, including Rick Santorum, Michele Bachmann, Sarah Palin and Herman Cain, Mourdock has a 10-point advantage over Lugar, according to a new poll released Friday.
"My hunch is that Mourdock is probably going to win. It's one of those places where people want more change," Gingrich said.
He added, however, that he will not be offering an endorsement in the race.
While Gingrich appealed for help to pay off his campaign debt by pointing viewers to his website, the former House speaker was also raising support for another cause Sunday morning. Gingrich, a big fan of zoo animals, sported a tie with polar bears, a move his spokesman R.C. Hammond said on Twitter was to mark his support for the St. Louis Zoo-the same zoo the former candidate was bitten by a penguin in April.