With Ohio Gov. John Kasich winning his home state Tuesday, along with its 66 delegates, he'll likely work on northeastern states such as New York, Pennsylvania and Connecticut. Meanwhile, Texas Sen. Ted Cruz will focus on the western states more compatible to his conservative message, former House Speaker Newt Gingrich told Fox News.
"This gives him a new burst of life," Gingrich said of Kasich during Fox's post election coverage.
The two-pronged approach will be the best chance of slowing down front-runner Donald Trump, he said.
"However, what you can say for sure is that the nominee is going to be named either Donald or Ted," Gingrich added, though he said Kasich can play a role in which of the two the nominee ends up being.
But a contested convention with Kasich as the nominee, as Kasich has hinted at, is "insane," Gingrich said.
"You live in an age of social media and television. Millions of people will have voted. You have two really strong personalities. Trump and Cruz are not exactly shrinking violets," he said. "The idea somebody is going to push those two aside? My hunch is, they would probably join forces to block any third person from emerging just out of sheer anger."