"The man standing before you was a Democrat when he picked up his first issue in a plain brown wrapper," Ronald Reagan told the crowd tonight at National Review's 30th anniversary celebration. "And even now, as an occupant of public housing, waits as eagerly as ever for his biweekly edition -- without the wrapper."

Charter subscriber Reagan praised the magazine's "witty, civilized pages" and the "terminal damage those pages have done to modern statism and its unrelenting grimness" in a speech before more than 700 of its faithful readers at the Plaza Hotel.

The gathering was a Who's Who of conservatism -- supplemented by neoconservatives, a few journalists and Tom Selleck.

The president said National Review and its editor and founder, William F. Buckley Jr., had contributed to such conservative victories as reduction in marginal tax rates and aid to the "Nicaraguan freedom fighters." National Review "is to the offices of the West Wing of the White House," the president added, "what People magazine is to your dentist's waiting room."

At the cocktail hour before dinner, Rep. Jack Kemp said he began reading the magazine while he was in college. "But I became a fervent reader in my first years in pro football when I had some reason to become conservative -- I was finally making some money."

That description also applied to the crowd. Tickets were $300 a couple,) $175 for singles for the dinner honoring the fortnightly that Buckley launched in 1955. He raised $200,000 then, according to his sister and managing editor, Priscilla Buckley, and published weekly until he hit "a financial crunch that has never ceased." National Review annually beseeches its 116,000 readers for funds to cover its $300,000 to $400,000 deficit. But last night, the talk was of its influence.

"It's a celebration of Bill Buckley's triumph," trumpeted Lewis Lehrman, chairman of Citizens for America, pumping hands and kissing cheeks. "And of his ideas. And of the election of President Reagan."

"A compass for a philosophy of America that, measured against reality, will assist in our voyage," intoned USIA Director Charles Z. Wick. "And if I'm elected . . . "

CIA Director William J. Casey, pronouncing the magazine "a great institution," reminded guests that "I incorporated it. I was Bill's lawyer when he started it 30 years ago."

Among those dining on chicken potpie a la Pat Buckley were (among the politicos) White House Communications Director Pat Buchanan; fundraiser Richard Viguerie; William Buckley's brother James, a federal bench nominee and former senator; and Nancy Kissinger ("I always agree with whatever Mr. Buckley says. Practically).

Roy Cohn attended, gaunt and pale but saying he was feeling "very much better" from a reported struggle with cancer.

The media contingent included Mike Wallace, John Chancellor, George Will, James Kilpatrick and Henry Grunwald of Time Inc. The evening was nevertheless off-limits to photographers (except for two for National Review) and television crews (except for one from William Buckley's "Firing Line" show). The three networks protested the decision.

Charlton Heston emceed after-dinner speeches by Kemp, Will, National Review Publisher William Rusher, Priscilla and William Buckley and their editors, and the president.

Heston said he was recruited for this task by William Buckley, who called to ask if he believed in free speech. Heston said he did. "That's wonderful, Chuck," the master of ceremonies quoted the editor as saying. "We'd like you to come East and make one."