As the Republican tent shrinks, Rush Limbaugh, arguably the most successful and influential radio host in American history, has emerged as its most prominent voice. No elected Republican--not John McCain, not Arnold Schwarzenegger, not Bobby Jindal--commands the loyalty of as many grassroots conservatives. Rather than sit idly by as conservatives find their bearings in the Age of Obama, Limbaugh, who played a crucial role in the 1994 Republican takeover of Congress, has decided to use this moment of Republican weakness and disarray to remake the Party of Lincoln as the Party of Limbaugh.

In his speech to the Conservative Political Action Committee (CPAC) last Friday, to lusty cheers from the crowd of young activists, Limbaugh savaged inside-the-Beltway conservatives for, in his view, surrendering to the forces of Big Government. Rather than adhere to the Reaganite gospel, these false prophets promise to win elections by mimicking the Democrats. "We will come up with our own version of it that is wiser and smarter, but we've got to go get the Wal-Mart voter, and we've got to get the Hispanic voter, and we've got to get the recalcitrant independent women. And I'm listening to this and I am just apoplectic."

As the co-author of Grand New Party, a book focused on how Republicans can win Wal-Mart voters, this part of the speech was of particular interest to me. By questioning conservative orthodoxy, Limbaugh said these self-described reformers are in fact selling out the movement for credibility with "cocktail elitists." Other sellouts include Republicans disappointed by Louisiana Governor Bobby Jindal's response to Obama's recent address to Congress. The night after Jindal's speech, Limbaugh did more than just stick up for Jindal--remarkably, he essentially said that Jindal's critics were dead to him. "I don't want to hear from you ever again if you think that what Bobby Jindal said was bad or what he said was wrong or not said well."

If this strikes you as a little thin-skinned, you're not alone. It wasn't just a handful of "cocktail elitists" who felt disappointed by Jindal's lackluster debut. Indeed, the criticisms of Jindal tended to come from his strongest supporters, who believe that he should have emphasized his success in making Louisiana's government more transparent, responsive and effective without breaking the bank. Yet that doesn't seem to matter to Limbaugh, who seems increasingly intolerant of even the slightest dissent. Even Newt Gingrich, the architect of the Republican Revolution who has long called for conservatives to sharpen their policymaking efforts, is suspect.

A few weeks ago, I found myself in an awkward spot. Shortly after President Obama's inaugural address, I was asked whether Rush Limbaugh was a negative influence on the future of the GOP. Though I've had my disagreements with "El Rushbo" in the past, I argued that he was not. Everyone loves conflict, and it's hardly surprising that many observers, on both sides of the political fence, have been talking up the prospect of a "Republican civil war." Yet at the time I was convinced that there was no need for a civil war, and I still am.

What Limbaugh fails to understand is that any successful political movement is built of both true believers and evangelizers. True believers, like Limbaugh and Sean Hannity, fire up the troops. They tell their followers exactly what they want to hear, and they instinctively resist any compromise of their hallowed principles. As a general rule, true believers live and work and worship among other true believers, and they like it that way. To the extent they engage the other side, the engagement takes the form of friendly but chilly mutual incomprehension or, more often, a shouting match. There is something admirable about conviction that runs this deep. But it limits the size of your audience. Every week Rush Limbaugh reaches an audience of over 13 million listeners--a staggering sum by any standard. Yet 13 million listeners plus their spouses, plus the family dog, plus a few dead aunts and uncles thrown in here or there, still doesn't add up to an electoral majority.

That's where the evangelizers come in. Evangelizers are in the business of making converts, and so they are obligated to make their way among people who are opposed--sometimes bitterly opposed--to their views. To succeed, evangelizers need to recognize the other side's strengths and to use its language. Just as missionaries would occasionally "go native" in foreign lands and abandon their original creed, there is a real risk that evangelizers will lose touch with their core beliefs. Yet other missionaries learned to adapt, to take the essentials of their faith and compromise it in such a way as to make it relevant and compelling to the locals.

It should hardly come as a surprise that true believers aren't always fond of evangelizers. After all, evangelizers tell true believers things they don't want to hear. Just as devout Saudi Muslims are quick to question the Islamic credentials of Bengali and Malay and American Muslims who mingle freely with nonbelievers, Limbaugh is enraged by the likes of David Brooks and David Frum and Jim Manzi and Ramesh Ponnuru, conservatives who consort with the liberal enemy. Though all of these writers and thinkers disagree amongst themselves about a great deal, they share a basic belief that the party needs to do more than just promise tax cuts we can't afford. And they recognize that a healthy political movement is always open to new ideas, and to questioning old convictions. During his CPAC speech, Limbaugh praised President Obama for his gifts as a communicator, and he expressed genuine sadness over Obama's misuse of those gifts. Much the same can be said of Limbaugh himself, who uses his obvious talent and cutting wit to do little more than ridicule his political opponents. True believers have their place. But right now, Republicans are in desperate need of evangelizers. And if Limbaugh really does manage to drive them out of his party, he'll find his merry band of Dittoheads age and shrink into oblivion.