George Bush and Edward M. Kennedy -- Massachusetts' native-son entrants in the Republican and Democratic presidential races -- were left wondering today whether the fickle voters of the commonwealth might administer the coup de grace to their campaigns Tuesday.

For Kennedy, still seeking his first victory over President Carter, the odds are that family loyalties will prevail and keep the flame of his challenge flickering a bit longer. But for Bush, seeking to recharge his batteries after his landslide loss to Ronald Reagan in New Hampshire, there is a distinct possibility of electoral disaster.

Today's Boston Globe poll of Massachusetts Republicans showed a pattern similar to that of the same paper's pre-New Hampshire poll, with Bush slumping from an early lead to a near-tie with Reagan, and all the momentum seemingly going toward the California conservative.

Reagan flew into Massachusetts today to try to nail Bush's coffin shut with two days of personal campaigning here and in Vermont, which also holds a primary Tuesday.

In both states, Bush is being held from the left by Sen. Howard H. Baker Jr. and Rep. John B. Anderson, who are waging struggles for survival -- meaning, in their cases, finishing at least third.

Baker, who beat Anderson by three points in New Hampshire, is favored to do so again in Vermont, where he has the backing of Gov. Richard Snelling. But in Massachusetts, where Anderson has spent more time than any other candidate, the Illinois liberal's appeal to independents and young voters could shove Baker into fourth place -- casting further doubts on the viability of his campaign.

In the past few days, the Republican drama has upstaged the Democratic fight in this predominantly Democratic state and region.

The Democratic primary in Vermont is a nonbinding advisory vote. Neither Carter nor Kennedy forces have made a major effort there, and Carter is favored to win, as he did in 1976.

Here in Massachusetts, Carter has gained the support of several leading Democrats, including Gov. Edward King and Speaker of the House Thomas McGee.

But the president's managers have been careful to say as often as anyone would listen that there was "no way" Kennedy could lose Massachusetts. The Globe poll, while showing some Kennedy slippage, still showed the senator ahead by 17 points, and the street talk is that most Democrats here would prefer to let the voters of another state -- like Illinois or New York -- end their favorite's troubled excursion into the presidential race.

California Gov. Edmund G. (Jerry) Brown Jr. is not contesting actively in either Massachusetts or Vermont.

The Bush-Reagan battle in both states has turned into a nail-biting affair, especially for Bush, who needs to win in his native region and deny Reagan further impetus for the four southern primaries in South Carolina, Florida, Georgia and Alabama coming up in the next nine days.

"The Massachusetts primary is tremendously important," Bush told supporters in Hyannis this afternoon. "It's going to sort out the fringe candidates and give someone momentum going South . . . . We've got to do well here and in Vermont."

Bush was organized early in both states, enlisting the help of both Republican National Committee members, key state senators and 11 of the 14 county GOP chairmen in Vermont, plus such prominent Massachusetts Republicans as Henry Cabot Lodge and Elliot L. Richardson.

But Bush's failure to get Snelling's support gave Baker an important ally in Vermont, and the governor has been putting on a late drive to boost the Senate minority leader's chances.

Even more worrisome to Bush is the upsurge of support in both states for Anderson, who has been getting the kind of publicity from the Globe and endorsements from other papers that candidates usually only dream about.

"Anderson is kind of the Gene McCarthy of the Republican Party," said Vermont GOP Chairman John M. Lindley III. "He's a guru to the college kids. He's winning all the high school straw votes, and it's got to have some impact on the adults."

What is true in Vermont is even more true in Massachusetts, with its huge student population. Here. Anderson also has the endorsement of former U.S. senator Edward W. Brooke and other leaders of the liberal wing.

Bush has been trying to halt the hemorrhaging on his left by campaigning nonstop in the two states since Friday ight and by arguing that neither Anderson nor Baker is a viable national candidate for those who want to stop Reagan. "When you vote for Baker or Anderson as New Hampshire showed, you help Reagan," Bush told an audience in Bennington, Vt., Saturday.

The Californian is in an enviable position. In 1976, he won only on-third one-third of the Massachusetts GOP primary votes and 15 percent (on write-ins) in Vermont, but he did that without making an appearance in either state.

He is believed to have a hard-core conservative constituency in both states comprising at least one-third of the vote, and he is not sharing it with anyone. John B. Connally and Bob Dole are invisible here, and three days ago, the Massachusetts leadership for Rep. Philip M. Crane defected en masse to Reagan.

An additional special factor working for Reagan in Vermont is the active support of the state's popular former governor, Deane Davis.

In the Vermont GOP primary, a candidate must win 40 percent of the votes to gain 10 of the 19 national convention delegates. Otherwise, all the delegates will be elected at the May 24 state convention, as will the 12 Democratic delegates.

In Massachusetts, both parties award delegates proportionally to the primary results, with 42 on the Republican side and 111 on the Democratic.

Robert Dawson, executive director of the Reagan campaign here, said that both states "look winnable" now for Reagan, and victories by the Californian would leave his opposition almost desperate for a place to stop him.