If you like calling Republicans fascists, then Joe Conason’s “It Can Happen Here: Authoritarian Peril in the Age of Bush” (St. Martin’s Press, 238 pages, $24.95) is the best book ever.

How about when the GOP disagreed with President Franklin Roosevelt’s domestic agenda? “In the time of crisis, when powerful figures in the corporate elite and the Republican party looked toward fascism for salvation, the American people chose democracy and the New Deal instead,” Mr. Conason writes. And the American Enterprise Institute’s Michael Ledeen? He “resembles the Fascist leaders he studied, who worshipped war and aggression as the most important hallmarks of a great nation.”

When the Mr. Conason’s opponents aren’t fascist, they’re communist. “As others have observed, the former Communists of the American neoconservative movement had changed their ideology but not their character,” he writes. “Torture, disappearances, and massacres were acceptable then; deception, illegal war and torture are acceptable now.”

If you don’t think that conservatives, neoconservatives, or the Republican Party are synonymous with fascism, and you find the comparison historically foolish and needlessly destructive to public discussion (after all, isn’t advocacy of fascism beyond the terms of civilized political discourse?) then “It Can Happen Here” might not be the right book for you.

Mr. Conason artfully inserts ellipses to dramatically alter the meaning of quotations. He cites White House Press Secretary Ari Fleischer’s oft-misquoted “watch what they say” comment as a veiled threat at comedian Bill Maher:

Standing behind the presidential podium, which bears the presidential seal, he said: “And that’s why… they’re reminders to all Americans that they need to watch what they say, watch what they do. This is not a time for remarks like that; there never is.”

In fact, Mr. Fleischer was responding to an appalling comment by a Louisiana congressman, John Cooksey, who said, “If I see someone come in and he’s got a diaper on his head and a fan belt around that diaper on his head, that guy needs to be pulled over and checked.” Here is the full comment, with the clarifying aside from Mr. Fleischer:

I’m aware of the press reports about what he said. I have not seen the actual transcript of the show itself. But assuming the press reports are right, it’s a terrible thing to say, and it’s unfortunate. And that’s why — there was an earlier question about has the President said anything to people in his own party — they’re reminders to all Americans that they need to watch what they say, watch what they do.

Beyond that, Mr. Conason collects the expected Bush-is-the-root-of-all-evil anedcotes — the idiotic public relations contract with commentator Armstrong Williams, the Valerie Plame mess, the Cheney energy task force, Ahmed Chalabi, Bush’s appointees to the Corporation for Public Broadcasting, and Ken Lay. In between, Mr. Conason breezily asserts disputable claims, such as “The neoconservatives showed relatively little enthusiasm for the war in Afghanistan.”

Among current political books, “It Can Happen Here” is not merely a well-trod path — it is the autobahn.

By contrast, Michael Tanner, author of “Leviathan on the Right: How Big-Government Conservatism Brought Down the Republican Revolution” (Cato Institute Press, 322 pages, $22.95) at least offers an argument more likely to generate a discussion than a partisan food-fight. Mr. Tanner contends that President Bush has led his party to ruin by abandoning any effort to reduce the size, budget, and regulatory reach of the federal government.

Mr. Tanner cogently makes his case that Mr. Bush’s big-government policies alienated key constituencies within the conservative movement and have rarely been clear-cut policy success stories. But the book slips when it tries to fully confront the fact that “small government” is easier to enact in theory than in practice.

Mr. Tanner directs readers to an ABC/Washington Post poll from June 2004. But if you actually look up the poll result on the Internet, you see the preference for “smaller” beat “larger” by only 50 % to 46 %. Similarly, a chart later in the book purporting to show steady popular support for smaller government stops in 2002.

“Small government” is only popular until you actually try to cut an actual government program, and then you’re portrayed as Scrooge on the cover of Time magazine, as Newt Gingrich found himself after the 1994 election. If you approach this book fearing that libertarians and budget-cutters underestimate the obstacles to their vision, Mr. Tanner is unlikely to dissuade you.

Mr. Tanner’s intelligence is obvious, but his sense of what works on the campaign trail isn’t. “Traditional conservatives operated from a position of humility when it came to what government could accomplish,” he writes. Perhaps, but any politician would be dismissed as unambitious and lazy if he dared offer only a “modest” agenda in today’s environment. The press has largely stopped trying to police the grandiose promises of politicians, and a large number of voters have been conditioned to expect the world on a silver platter from their aspiring leaders. John Edwards declared that Christopher Reeve would rise and walk when John Kerry was elected president.

A central tenet of traditional conservative thought is that there is no such thing as a free lunch. Persuading voters that they can’t get something for nothing — no matter what utopia liberals promise — appears to be one of the greatest challenges facing politicians of the right today.

Mr. Geraghty writes “The Hillary Spot” blog for National Review Online.