Since Donald Trump descended down the elevators of Trump Towers to announce his candidacy, most conservative pundits disparaged him and then fumbled to understand why Republican and Independent voters support the man they once dismissed. Ann Coulter, of course, is not a typical conservative pundit. Her excellent new book, In Trump We Trust: E Pluribus Awesome!, both defends Trump against the frivolous slurs and explains his appeal.

Coulter easily dispenses with the most tired criticisms of Trump from erstwhile conservatives. To those who object to his brash style and blunt speaking, Coulter responds that all the “old-school Waspy understated, dry, less-is-more, antique leather, sturdy wood-and brass” types support left wing positions. Donald Trump’s bold and gauche style immunizes him from the elite peer pressure. A more modest man would be cowed into abandoning his anti-establishment positions on immigration, trade, and political correctness.

To the “Never Trump” conservatives who disagree with or do not trust Trump to enact their preferred positions on government spending, abortion, or other issues, she notes the obvious point that if Hillary Clinton appoints the next three Supreme Court Justices, these issues are lost. Coulter also makes the more profound argument that continued immigration will usher in “invincible Democratic majorities,” which will make it impossible to enact any conservative policies.

Not only is immigration the most pressing issue facing our country, Coulter shows that it motivated a record number of Republican voters to support him in the primary. Contrary to the claims Trump’s personality drove his support, Coulter credits his America First platform, noting it’s “not as if the GOP is lousy with candidates who would build a wall, bring back jobs, and avoid wars–but voters settled on the reality TV star.”

At his rallies, Trump supporters chant, “Build A Wall” not “Reform Social Security” or “Protect Ukraine’s National Sovereignty.” Trump’s closest competitor, Ted Cruz was mimicking his policies by the end of the campaign, while the two pro-amnesty establishment favorites Marco Rubio and Jeb Bush floundered. The combined Cruz-Trump vote “represented what this party wants: a wall, deportation, and a lot less immigration.” This, she notes, is completely at odds with the party elite’s cheap labor agenda.

Unfortunately, most of the GOP establishment has not gotten the message. Trump destroyed their preferred candidates despite opposition from GOP mega-donors, the bulk of the conservative media, the entire consultant class, and almost all elected Republican officials. Nonetheless, they think that with a “little tinkering,” they can return to the good old days of Bob Dole and John McCain.

Coulter concludes the book by noting that this is not an option. The GOP must become a “New Trumpian Party,” which responds to the interests of its voters rather than donors and consultants, “and end up a better stronger party or it will go the way of the Whigs.”

Coulter’s previous book, Adios America, came out just as Trump announced his candidacy. While derided as extreme, it helped put immigration front and center of the 2016 campaign. When Coulter predicted a Trump victory just three days after he announced on Real Time with Bill Maher, the audience and her co-panelists laughed at her. They aren’t laughing anymore. If Republicans want to win in 2016 and beyond they should start taking Coulter and In Trump We Trust’s message seriously.