In a new book, Sam Tanenhaus, the New York Times Book Review editor, proclaims the death of conservatism. Movement leaders’ devotion to “radical” antigovernment ideology, Tanenhaus argues, has left them “trapped in the irrelevant causes of another day, deaf to the actual conversation unfolding across the land.”

Judging by the massive crowd on Saturday that descended on Washington for the 9/12 March, you’d have to be deaf not to recognize that small‐​government conservatism remains a vital part of the national conversation.

If you’ve been fed a steady media diet of MSNBC over the last few months, though, you could be excused for fearing a Pennsylvania Avenue takeover by a rabble of pitchfork‐​wielding cranks and extras from “Deliverance.” But the crowd — “in excess of 75,000 people,” according to a D.C. Fire and Emergency Medical Services spokesman — was made up of orderly, pleasant, middle‐​class Americans from all across the country.

In my two hours at the protest, I didn’t see a single “Birther” sign, and spied only one racially insensitive caricature. “Many of the signs,” the liberal Center for American Progress alleges on its blog, “attacked President Obama using explicit racial and ethnic smears” — a claim that’s simply false.

It used to irk liberals no end when conservatives crashed peace marches, snapped pictures of the nuttiest signs, and used them to condemn all Iraq war opponents as troop‐​hating traitors. That didn’t stop CAP’ers from trying the same tactic, to little avail.

The gallery of “racist, radical portrayals” they posted after spending hours looking at tens of thousands of signs contains few that fit the bill. (If an “Obamunism” placard featuring the president in a Che beret gives you the vapors, you’re probably too delicate to watch cable news without prescription tranquilizers.)

Surprisingly, for a march held the day after the 9/11 anniversary, the war on terror wasn’t a prominent issue. Very few of the signs reflected the militarism and fearmongering that’s been all too popular on the Right in recent years. The most common 9/12 themes were pro‐​Constitution, anti‐​czar, anti‐​Obamacare, and anti‐​bailout.

Amid the sea of hand‐​lettered placards were quite a few that warmed this columnist’s cold libertarian heart, like “I am John Galt” and “What Would Mises Do?” “Austrian Business Cycle Theory!” blared a sign carried by a white‐​haired fellow, obviously pleased with his own erudition. Several 9/​12’ers carried signs reading simply, “Liar” — a smart choice for the dedicated protester, as it will rarely have to be replaced from election to election.

None of this is to suggest, however, that the 9/12 March showed all was right with the Right. Movement conservatism clearly has a long‐​term demographic problem.

The crowd was disproportionately middle‐​aged, and whiter than a Jimmy Buffett concert. Some of the “outreach” efforts on the main stage were condescending and embarrassing, as when the organizers handed the microphone to right‐​wing rapper “Hi‐​Caliber.” Suffice it to say that “Republican hip‐​hop” is every bit as excruciating as the concept suggests.

The Republican leadership’s decision to position the party as Medicare’s most passionate defender may be tactically smart in the short term, but it’s hardly consistent with limited government, to say nothing of fiscal sanity.“Deep Medicare cuts are just one of the mounting reasons why Americans are losing faith in the Democrats’ government takeover of health care,” House Minority Leader John Boehner declares on his web page, oblivious to the contradiction.

It would be comforting to think that the GOP is out of touch with its conservative base here, but that’s unlikely. A 2007 Harris poll showed that only 2 percent of Republicans support Medicare cuts to help close the deficit.

Even so, the public seems increasingly resistant to new big‐​government schemes. In a recent column, Andrew Kohut, president of the Pew Research Center, argues that Medicare could never have passed in the current political climate: “Broad distrust of government — which was not evident in the 1960s — is an important reason why Americans are reacting so differently to health care reform in 2009 than they did in 1965.”

That rising distrust of big government — of which Saturday’s march was the most vivid recent example — shows this much at least: “The death of conservatism” has been greatly exaggerated.