Conservative talk radio host Rush Limbaugh opened his show Wednesday literally laughing out loud at how GOP presidential nominee Donald Trump was able to swing the party base to support what he called amnesty for illegal immigrants while spoiling conservative author Ann Coulter's brand new book release.

"Could you imagine what it's like to be Jeb Bush today?" Limbaugh said of one of Trump's former GOP rivals who ran unsuccessfully pushing a legal path to citizenship.

"Who knew?" Limbaugh said, clearly amused. "First they tried Marco Rubio. They tried the Gang of Eight. They tried Jeb Bush."

Limbaugh noted that Republicans even sent "emissaries" to meet him in hopes he would fall in line, all to no avail.

"They tried everybody they could think of to try to convince the Republican base to support some form of amnesty for illegal immigrants, and … sorry," he said between laughs. "I know it frustrates you to hear me laughing. Sorry."

He even took a poke at Coulter, whose new book "In Trump We Trust" was just released this week. In it, she says Trump could only hurt his candidacy by reversing on immigration – he's vowed to build a wall along the Mexican border and deport all illegal immigrants.

But Trump did just that in an interview aired Wednesday with Fox News Channel's Sean Hannity. Trump suggested he was open to "softening" his stance, and might deport only those who are criminals while allowing the otherwise law-abiding to pay back taxes and be allowed to stay.

That drew a mixed response from the Hannity audience, though most supporters have continued to defend him. Coulter, however, took to Twitter to blast her candidate's new position.

"I don't see a lot of people preparing to abandon Trump over this," Limbaugh said, but added, "maybe Coulter" would. "Who knows what she's gonna do. I mean, her book hits, and it's just had the rug pulled out from under it."