A portrait of Calvin Cooldge now hangs in the White House Cabinet Room -- Ronald Reagan's way of honoring his favorite president. Last night in Alexandria, party guests paid tribute to "Cool Cal's" 109th birthday -- and to the man who now has his job. "They both are non-workaholics," joked columnist Robert Novak of Coolidge and Reagan. "No president can hurt you when he's sleeping."

With only a portrait of William McKinley in sight, 75 fellow Coolidge boosters gathered at the home of Reagan's Northeast campaign coordinator, Roger Stone, for the birthday celebration.

"Actually Coolidge was born on the Fourth, but not everyone could make it down Saturday," said Stone, munching on a bacon-wrapped chicken liver. "Cal was a simple man, but he would have supported President Reagan's tax plan. He was a great supply-sider."

Coolidge, president from 1924-1928, died in 1933. During his lifetime, he nurtured his reputation for being taciturn and had a well-known liking for simple foods, pickles most of all. But last night's guest -- including attorney Roy Cohn, NCPAC chairman Terry Dolan and direct-mail campaign whiz Richard Viguerie -- were treated to mushrooms stuffed with churizo sausage, Brie topped with sliced almonds, torted asparagus rolls and French bread from Ridgewell's while the conversation flowed freely.

Although most of the guests were firmly in the Reagan camp, not everyone had an opinion on the man who coined the now-famous credo, "America's business is business." Dolan said, "Calvin Coolidge was too much of an activist president for me . . . I'm just kidding, honestly. I don't know enough about him."

Dolan, 30, said he became a conservative in 1974: "Nixon converted me. He's the most liberal president we've had -- more bureaucracy, detente, deficits. I think George McGovern would have been less liberal because he would have had the opposition of the Republican Party."

Roy Cohn, just in and tan from time spent at his Cape Cod beach house, engaged Viguerie in a discussion about Cohn's alma mater, Columbia University.

"You'll love this one, Dick," said Cohn. "I just got through writing Columbia a letter. They're creating a chair in the name of Paul Robeson [the late black actor and political activist], and Father [Robert] Drinan [the former Democratic congressman from Massachusetts] gave the commencement address. A beautiful double-header! I told them that in 1981 that was a little ridiculous."

Viguerie, dressed in a dark pin-striped suit, just smiled. Later he reflected on the future of his direct-mail operation for conservative political candidates. He said he hoped to quadruple the size of the organization by 1984. "The conservatives have come a long way, but we still have a long way to go," he said. "We hope Ronald Reagan will run again, but if he doesn't, we have to find a strong conservative."

Any suggestions?

"Oh, Helms, Hatch, Laxalt, Kemp, there's a lot of good people out there," said Viguerie, the author of "The New Right."

What about ol'Cool Cal?

"My knowledge of Calvin Coolidge is not extensive," said Viguerie. "You'll have to ask Roger."

Dressed in madras pants, a J. Press tie decorated with crossed tennis racquets, and a lime green watchband as bright as kryptonite, Roger Stone, along with his wife, Bitsey, greeted the guests, mingled and generously praised Coolidge.

Everyone seemed at home, even John Deardourff, a media aide to liberal and moderate Republicans, including Gerald Ford.

"I like Roger, and I've had a strong feeling that this was a big Party and there was room for everyone. Of course, not everyone has always felt that way," said Deardourff.

"This is an ecumenical Republican gathering," said Stone.