Between campaign stops in Texas and Iowa, Vice President Bush made a quick detour to Maryland today and became the first top presidential surrogate to campaign for Republicans this year in this heavily Democratic, working-class state.

But rather than appear on behalf of the two most visible GOP candidates, Lawrence J. Hogan and Robert A. Pascal, running for U.S. senator and governor respectively, Bush ventured to a rain-soaked bull roast for Rep. Marjorie S. Holt, the only Maryland Republican in the House.

Hogan invited Bush and President Reagan to campaign for him in Maryland, one of six states Reagan lost in 1980, but top GOP strategists reported last week that the president will not come to the state. Bush has made no commitment, but said he hopes to return if his schedule permits.

Today, five weeks before the Nov. 2 election, Hogan and Pascal were relegated to subordinate roles. Each sported blue and orange "Holt" buttons in their lapels and sat at the rear of a small stage bedecked in red, white, and blue, looking on quietly as Bush and Holt extolled each other's virtues from the podium. "Holt Welcomes Bush" banners were hanging from the roof where 1,000 ticket-holders feasted on barbecue, cold cuts, mashed potatoes, corn, ham, and 2,500 pounds of beef spitted over charcoal.

It was no surprise that the first White House emissary to come to Maryland for a campaign stop chose to visit Anne Arundel County, a stronghold of mainstream conservatism that has become one of the state's few political oases for Republican politicians. It was not surprising, either, that Bush focused his attention on Holt, a staunch conservative who is virtually assured reelection after serving in Congress 10 years. She was also one of the first to endorse Bush for president in 1980.

Bush, however, tried to give Hogan and Pascal rousing endorsements, particularly in the wake of reports that the White House will provide only limited resources to Hogan's campaign against incumbent Democratic Sen. Paul S. Sarbanes.

"You have a real opportunity to hit a real blow for liberty here," Bush said during his 10-minute speech. "Both Pascal and Hogan are outstanding people. Both have a record in county government. Larry Hogan . . . is going to give Sarbanes a run for his life."

But for the most part, Bush and Holt focused on Reaganomics and the larger Republican cause.

"Americans are fair," Bush said. "They know you can't work miracles on the economy in 11 months. But the Democrats knock the heck out of Ronald Reagan and try to win doing that. They don't remind you what the interest rate was when former president Carter left office."

As the rain drizzled on, he said, "These guys the Democrats sound like they're running for president. Some of them probably are. Sen. Edward M. Kennedy's trying to lose 40 pounds and former vice president Walter F. Mondale's trying to lose Jimmy Carter."

Less than an hour after his limousine arrived, Bush and his wife left.