Gingrich, in the islands promoting his book "Real Change," predicted in a telephone interview from Maui that Obama will surge ahead of Sen. Hillary Rodham Clinton for the Democratic nomination and pose a significant challenge to Republican Sen. John McCain.
"If McCain can't communicate a vision of dramatic change for America, he'll just lose, whether he appeases conservatives or annoys conservatives," said Gingrich, architect of the "Contract With America," which helped Republicans take the House and Senate in 1994.
McCain will have a tough time getting elected if he becomes known as a candidate representing more of the same, he said.
Hawaii's Democratic caucus will be held Tuesday.
"I don't see how the Clintons can draw a distinction with Obama, so I think Obama will be the nominee," Gingrich said. "To win this year, you have to be the candidate of real change."