Watch: Stephen Colbert tries to treat John Kasich's run for president as seriously as he can

After Donald Trump's win in the Indiana primary Tuesday night, just about everyone on Earth assumes Trump will be the Republican nominee for president.

But not John Kasich. The Republican governor of Ohio remains in the race, arguing he can somehow pull out a win at a contested convention. Kasich and his supporters seem to believe this so strongly, in fact, that a pro-Kasich Super PAC recently released a video imagining Kasich winning the nomination — something that seems impossible today.

On Wednesday, Stephen Colbert argued this didn't go far enough. "Why stop at the nomination?" Colbert said. "I can imagine an ad that's even more optimistic."

In the ensuing ad, a narrator imagines a world with "President John Kasich": "What a long, strange trip it's been. How did he go from third place in the 2016 Republican primary to the most successful five-term president in American history? … And after Barack Obama resigned early to make way for President Kasich, he balanced the budget, defeated ISIS, and repelled the spider beasts from space. Then, with only three seconds left, he threw the winning pass in the Super Bowl — a pass caught by John Kasich."

Watch: Why Donald Trump can't become a "moderate"