Three months before the Maryland presidential primary, George Bush has virtually locked up the support of the state's Republican Party hierarchy.

Allan C. Levey, the Montogmery County dentist who services as state GOP chairman, still maintains a public posture of neutrality. But his preference for Bush, as one party official put it, "has become the worst kept secret in the state."

Levey has been maneuvering to lure Bush into the state as the one and only guest speaker at a large fund-raising dinner for the state party sometime during the week before the May 13 primary. With unprepressed delight, Levey says the timing of the affair, and the selection of Bush as the star attraction, "is just coinciquence."

Below Levey in the state party's official structure is the first vice chairman, Joan Athen of Columbia, who plans to run in the primary as Bush delegate. The party treasure, Jeanette Wessel of Baltimore, is an active Bush supporter, and the party secretary, Arlene Baybutt, is Bush's Talbot County chairman. And Levey's 12-year-old son, Steve, is a Bush youth coordinator in Montogomery County.

In southern Maryland, Bush has garnered the support of U.S. Rep. Marjorie Holt, one of the top four elected GOP officials in the state. And out in the western hill country traditionally the strongest Republican region in the state, the former member of Congress, CIA director and national party chairman has picked up endorsements from the two state senators -- Edward Thomas of Fredick and Edward Mason of Cumberland both of whom plan to run as Bush delegates.

Most of this Maryland support for Bush has emerged since the Connecticut native with a Texas drawl rocketed out of the Iowa caucuses as a candidate to be reckoned with around the country. As Mason Said: "I liked him before Iowa, but I was waiting to see whether he could put together an organization to win."

Bush's standing in Maryland was also boosted, according to many state Republicans, by Sen. Howard Baker's (R-Tenn.) decision to back out of a state party fund-raiser at the last minute.

"Maryland is dominated by moderate Republicans, and I think this was a Bush-Baker state until Baker pulled out of the dinner," said Levey, who had bitterly attacked Baker for his decision to go to a gathering in Maine instead of the fund-raiser in Prince George's County in late January. "I think Baker half-killed himself by that move."

Baker's Maryland campaign chairman, state Sen. Howard Denis (R-Montgomery), yesterday accused Bush partians of "manufacturing" a dispute over Baker's dinner cancellation, which Denis said was the sort of practical campaign decision that all candidates must make from time to time.

While saying he did not want to make an issue of the state party's efforts to bring Bush into the state for the fund-raise in May, Denis added: 'The state party should be very careful about tilting to one side or another.If they're not, it could create some very bad feelings."

Denis said people in the Bush camp had grown so "cocky" since the Iowa victory that they "probed me" to see it he would switch allegiance. He rejected the offer, confident he said, that the pecking order of Republican candidates would change many times between now and may.

"Some people are making premature motions which may not be in their best interests or the best interests of the party," said Denis. "The winds of politics change so rapidly that some leaders should exert more caution. They may be swimming to a sinking ship."

It was only a few months ago that John Connally, the former Texas governor, was being pushed in the upper circles of the state GOP as the "Hot" candidate. Connally won the support of Gerard Holcomb, a financier from Prince George's who is a close Political associate of County Executuve Lawrence Hogan.

Although there were no public commitments at the time, many state Republicans assumed that Holcomb, by endorsing Connally, was privately bringing Hogan and Levey with him.Levey, too is a close associate of Hogan.

"Connally rolled into the state and picked up a lot of support," said one party official. "But now he looks like a loser and those people are very embarrassed. They are looking for a way to salvage their positions."

Hogan has not taken sides in the presidential race and is not expected to do so until after the primary. He will be one of six at-large state delegates to the Republican National Convention in Detroit. The other five likely will be Sen. Charles McC. Mathias, U.S. Reps. Robert Bauman adn Holt, Levey, and Republican National Committeewoman Louise Gore.

Of those six, only Holt and Gore have endorsed candidates -- Holt going for Bush and Gore supporting Connally.

Bauman, the voice of conservatism from the Eastern Shore, is said to be torn between Ronald Reagon and U.S. Rep. Philip M. Crane (R-Ill.), whom he succeeded as leader of the American Conservation Union.

At this point, Reagan and Bush are the only GOP candidates who have brought in professionals to run their state campaigns.

Billy Lacy, a consultant from Virginia, was hired by the Reagan camp to run the day-to-day operations in Maryland. Lacy has set up an office in Wheaton and, by his account, has traveled some 3,000 miles around the state since early January with his boss, state campaign chairman Don Devine, a University of Maryland professor.

The Bush coordinator in Doran Gunderson, a party activist from Wisconsin who worked for Bush at the Republican National Committee. Above Gunderson, as the co-chairmen of the state Bush effort, are former U.S. senator J. Glenn Beall and Jane Gude, the wife of former member of Congress Gilbert Gude.