Will Ferrell returned to "Saturday Night Live" as George W. Bush to make a hilarious announcement: The ex-commander-in-chief is running for president again.

"The field of Republicans out there is so messed up, I figured, it makes you miss me, doesn't it? And that's saying a lot," Ferrell said.

Ferrell joked about the GOP contenders, from Donald Trump to Ben Carson to Jeb Bush.

He took issue with Carson's neurosurgeon background, remarking that "running the country is not brain surgery... trust me, I know."

Ferrell said Trump's call to keep Muslims out of the U.S. is "impossible to implement."

"That's like saying, 'Let's keep all the leprechauns out.' We tried tiny leprechaun internment camps in the late 1920s, and as you all know, it totally backfired. Leprechaun relations have never recovered since, that's why they are so hard to find," he said.

The "Saturday Night Live" vet dismissed candidates Marco Rubio and Ted Cruz.

"Rubio and Cruz... sounds like a Miami law firm," he said.

But he had a soft spot for Carly Fiorina.

"She got fired from her job, she got her butt kicked in a Senate race, she's not qualified in any way to be president," he said. "In many ways, she reminds me of me."

He even took aim at Jeb Bush.

"You gotta admit, it's a pretty good plot twist when I turned out to be the smart one," he said.

Ferrell ended the opening monologue by comparing running a government to driving a school bus.

"You don't want a crazy person driving that bus. You want a simple, underachieving, not very educated but reliable guy behind that wheel. Someone with a steady hand who will be on time and get into one or two but no more than four accidents a year," he said. "You already know that someone, and that someone is me."

Watch the hilarious monologue above.