For a long time it was easy to discount Ted Cruz as a credible presidential candidate. As a junior senator with more ambition than power, Cruz has sought to pull the Republican party down around him, as quick to fight with his own leaders as he is the Democrats. He has often been portrayed in the media as a demagogue with a narrow base of support. Many of his colleagues in Congress, including fellow Republicans, consider him a blowhard, someone best ignored or occasionally mocked but certainly not a politician to be taken seriously.

Well, the time has come to take Cruz seriously. The man who pulled off one of the great upsets in Texas politics—defeating then–lieutenant governor David Dewhurst in the U.S. Senate primary in 2012—has joined the top tier of presidential candidates. His campaign has raised more money than any other. As of press time, he sat third in the latest Iowa polls, behind Ben Carson and Donald Trump. He seems well situated in New Hampshire and South Carolina. As Frank Bruni recently wrote in the New York Times, Cruz “seems to be positioning himself as the ultraconservative fallback—the rabble rouser in the bullpen—if angry voters rethink Trump or Carson and want an establishment-vilifying candidate with at least some government experience.” Cruz’s crowd-pleasing performance at the October 28 Republican debate, in Colorado, which was praised across the media spectrum, earned his campaign a boost in fund-raising and a fresh wave of momentum. That same week, Chris Cillizza at the Washington Post proclaimed that Cruz is “running the best campaign of any presidential candidate.”

He still seems too deeply unpopular with the general electorate to actually win the White House. (Presidential races are essentially likability contests, and as Cruz said in the Colorado debate, “If you want someone to grab a beer with, I may not be that guy.”) But that’s not the point. Whether Cruz’s campaign ends in the primary or the general election, the popularity of his rhetoric among the Republican grass roots should be worrisome to all Texans. That’s because he has not been a senator for all Texans. Rather, he appeals to a wing of the GOP that speaks its own language.

A Cruz speech on the campaign trail should come with a decoder ring. Take his appearance in late September at the Values Voter Summit, in Washington, D.C. He began with a few inside jokes. Standing next to the lectern—Cruz prefers to prowl the stage with a wireless microphone on his lapel—he touched the unused teleprompter. “I have to ask, what are these things for?” The crowd knew where he was headed—“It’s for Obama!” called a voice from the audience—and Cruz delivered the desired punch line: “Is Barack Obama coming?” Cruz chuckled and continued with what seemed like the opening monologue for a tea party version of the Tonight Show. “Yesterday, Pope Francis was in Washington. . . . I have to say the press conference was a little awkward. ’Cause every time the reporters addressed a question to ‘Your Holiness,’ Barack Obama answered.” The crowd loved it.

But then things grew a lot less funny. “If I’m elected president, let me tell you what I intend to do on the first day in office. The first thing I intend to do is rescind every single illegal and unconstitutional executive action!” This sounds like a line only a law school class would understand, but the applauding audience clearly knew exactly what he meant. It’s primarily a response to Obama’s executive order on immigration but also to some of his actions on Obamacare, which Cruz has argued are illegal, though they have not been overturned in court.

He later thundered that another thing he intends to do on his first day in office is “instruct the Department of Justice and the IRS and every other federal agency that the persecution of religious liberty ends today!” Persecution of religious liberty? No, you didn’t miss a memo: the First Amendment remains in effect. This line is a catchall that covers a range of perceived persecutions of Christians, including the recent legalization of same-sex marriage.

Cruz continued, “That means every serviceman and woman can worship the Lord God Almighty with all of his heart, mind, and soul. And his commanding officer has nothing to say about it!” Now, even a reasonably serious observer of politics might have to Google this one. Cruz was seemingly referencing an effort by the Navy to kick out a Pentecostal chaplain, who spoke against homosexuality and premarital sex, for being “unable to function in the diverse and pluralistic environment,” according to his commander. (The Navy dropped the effort, allowing the chaplain to retire.)

His next item? “Rip to shreds this catastrophic Iranian nuclear deal. . . . Under no circumstances will Iran be allowed to acquire nuclear weapons. And if the ayatollah doesn’t understand that, we may have to help introduce him to his seventy-two virgins.” Having just insinuated the assassination of a sovereign country’s supreme religious leader, he laughed and so did the audience.

“That’s day one,” he said. “There are three hundred and sixty-five days in a year. Four years in a presidential term. And four years in a second term. By the end of eight years, there are going to be a whole lot of newspaper reporters and editors and journalists who’ve checked themselves into therapy.”

Oh, indeed there would be. Perhaps not for the reason Cruz implies—that the media is inherently liberal—but because journalism is, or at least is supposed to be, a profession devoted to fact. Politics, as we have increasingly seen lately, is not, and none of the serious presidential contenders have divorced themselves from fact as often as Cruz has.

All politicians exaggerate and deliver applause lines to friendly audiences, but Cruz blows the dog whistle better than anyone. He frequently starts with an established fact and exaggerates it to the point of distortion. That’s how the problems with the implementation of Obamacare, and Cruz’s perfectly legitimate ideological objections to the law, became “Obamacare is killing jobs and our economy,” as he posted on Facebook in late 2013. Whatever you think of Obamacare, this statement simply isn’t true; in the two years since the law was fully implemented, the U.S. has added about five million jobs, according to the Bureau of Labor Statistics.

Take another example. In a March appearance on Late Night With Seth Meyers, Cruz was asked about climate change and said this: “Debates on this should follow science and follow data. And many of the alarmists on global warming, they’ve got a problem ’cause the science doesn’t back them up, and in particular, satellite data demonstrate that for the last seventeen years there’s been zero warming—none whatsoever.”

Cruz once again starts with a kernel of truth. In the past seventeen years, there has been little overall warming of the planet. By itself, that claim is largely true. But the time frame isn’t an accident: 1998 was one of the hottest years on record, thanks to El Niño, so starting there and using such a small sample size intentionally obscures the planet’s warming trend. Widen the sample—go back thirty or fifty years—and it becomes clear that the average temperature is increasing steadily. Cruz surely knows this. Given the obvious falseness of his statement, and the venue, this seems intentionally provocative.

So does another term Cruz often employs: “Washington cartel.” Asked recently on Meet the Press what that means, Cruz said, “I describe the cartel as career politicians in both parties who get in bed with lobbyists and grow and grow and grow government.” Here again, Cruz’s foundation is a basic fact: politicians often have close relationships with lobbyists, and corporations and the wealthy wield undue influence in the corridors of power. But his use of the loaded word “cartel” implies a criminality, even illegitimacy, as if members of Congress and lobbyists are engaged in racketeering. It plays into Americans’ worst suspicions about their government. There is assuredly corruption in Washington, as ever, but that’s not Cruz’s real objection.

What really bothers him is that Republican leadership won’t “stand on principle” or “do what they promised.” This essentially means they are not following Cruz’s agenda of implementing a flat tax, abolishing federal departments like the IRS, repealing “every word” of Obamacare, and shutting down the federal government over Planned Parenthood. But those issues are nonstarters with most Americans (except maybe the part about the IRS). A recent poll by USA Today found that 73 percent of Americans opposed a government shutdown to force the defunding of Planned Parenthood.

He calls this the “Republican party’s surrender politics,” which was the headline of a recent op-ed Cruz wrote for Politico in which he, displaying his rhetorical agility, at once advocated for shutting down the government over Planned Parenthood and blamed Obama for trying to shut down the government over Planned Parenthood. With Obama in the White House—and not enough Republicans to override a veto—the GOP had no chance for success. But Cruz portrayed the GOP’s reluctance to engage in a political suicide mission as gutless, even duplicitous.

The Planned Parenthood episode felt remarkably similar to the government shutdown over Obamacare, in 2013. Despite Cruz’s insistence that the GOP could succeed in defunding Obamacare, there was no way to win. The president would never agree to gut his signature legislation. This was perhaps the essential Cruz moment. He claimed that his side could win when it clearly could not. He then blamed the predictable defeat on a Republican leadership that couldn’t accomplish the impossible.

This kind of approach has the GOP worried. Following Mitt Romney’s loss to Obama, in 2012, the Republican National Committee produced an analysis of where the party stood. The report’s authors wrote, “The Republican Party needs to stop talking to itself. We have become expert in how to provide ideological reinforcement to like-minded people, but devastatingly we have lost the ability to be persuasive with, or welcoming to, those who do not agree with us on every issue.”

Rather than heed that warning, Cruz is turning his party into the skid. That may help his individual political fortunes, but at what cost? We have seen the impact in Texas, where the slice of the GOP that loves Cruz has gained enormous influence. Before Cruz won his seat in the U.S. Senate, Ken Paxton was an obscure state representative, Sid Miller was out of politics, and Dan Patrick was a vocal though ineffective state senator. Now Paxton is attorney general (indicted on three felonies), Miller is agriculture commissioner (and has defended deep fryers in schools), and Patrick is lieutenant governor. By showing how to harness the passions on the right, Cruz has led the way—and in Paxton’s case, essentially boosted him into office by promoting his campaign. Meanwhile, our political debate has, at times, become severed from reality, dominated by one absurd issue after another, from the conspiracy theories over the Jade Helm military exercise to the threat of sharia law to the supposed widespread discrimination against Christians.

And that’s not healthy. How can there be constructive dialogue in Washington and Austin when the most energized segment of the Republican party views such compromise and collaboration as defeatist? Cruz is championing the politics of delusion, and the consequences will have a profound effect on all of us.