Momentum - that is what the Vermont primary is all about. For Gary Hart it is an opportunity to demonstrate that his victory over Walter Mondale in the Democratic primary in neighboring New Hampshire was not a fluke.
For Mr. Mondale, Vermont is an opportunity to regain some of his own campaign momentum as well as to slow that of the Hart campaign.
Though there are no delegates at stake in tomorrow's Vermont primary (delegates will be chosen at April caucuses), the election is seen as a potential strategic asset - a stepping stone on the road to the Democratic National Convention.
It is the only primary in the country on March 6 and it falls one week before the critical ''Super Tuesday,'' when 613 delegates from nine states, plus American Samoa and Democrats abroad, will be decided. Those 613 represent approximately one-third of the delegates needed to win the Democratic nomination for president.
Senator Hart is looking for a string of successes or strong showings this week in Maine, Vermont, and Wyoming to keep him in the national spotlight as a winner and propel him into a strong position on Super Tuesday.
Mondale is taking a long-term approach to the campaign, expecting it to stretch all the way until the July Democratic convention in San Francisco. His strategy is to use his chief asset - Democratic organization support - and focus his effort where delegates are at stake. As such, Mondale was not expected to make any other personal appearances in Vermont prior to tomorrow's vote.
Hart was scheduled to be in the state today.
Though Mondale has the backing of well-known Democrats such as Sen. Patrick Leahy and gubernatorial candidate Madeleine Kunin, as well as statewide support within the established Democratic organization, the Mondale camp faces a tough task in Vermont. It is working against a Hart campaign catalyzed by the victory in New Hampshire.
Since New Hampshire, the number of Hart campaign offices have increased from two to eight statewide. Many of them are staffed by young Hart workers flown in from Iowa and New Hampshire.
Richard Moe, Mondale's former chief of staff in the White House, who was flown in last week, complains that the Mondale campaign is being outspent in Vermont.
''Hart is going for quick momentum,'' Mr. Moe says.
He likens the current primaries to a race between a sprinter and a long-distance runner.
''We are pursuing a long-range race here. We are going where the delegates are. When the delegates are here, we will be back here,'' Moe says.
Of particular concern to the Mondale camp is the potential that a large number of Republican voters may cross over and vote on the Democratic ballot where there is a contest. Vermont voters are given the option of voting on either the Democratic or the Republican primary ballots. President Reagan is running unopposed on the Republican ballot.
''Republicans will participate in the Democratic primary, and they are likely to vote for the non-Mondale candidate,'' says Garrison Nelson, a political science professor at the University of Vermont.
Political observers generally agree that a similar crossover vote, which helped John Anderson finish strongly in Vermont in 1980, may well give Gary Hart an extra push this year.
Jesse Jackson, the third and only other active Democratic contender on the Vermont ballot, is in a race of his own in Vermont. Mr. Jackson must field at least 10 percent of the vote to maintain his campaign's eligibility for federal matching funds.
Early last month, Jackson was considered a strong candidate to place second in Vermont after Mondale. He had attracted more than 1,000 Vermonters to a political rally in Montpelier on Feb. 5 - the largest such rally this campaign season - and was greeted enthusiastically throughout the state. But political observers say his Vermont campaign has stalled in recent weeks following the Jewish slur controversy and Hart's New Hampshire victory.
Sen. John Glenn, according to campaign aides, made a conscious decision not to enter the Vermont primary, preferring instead to concentrate his campaign in the South, where a large number of delegates are at stake next Tuesday. Glenn also pulled out of Maine in favor of a southern push.
Campaign workers for George McGovern are organizing a last-minute write-in effort in Vermont. Mr. McGovern is making an all-or-nothing push in the March 13 Massachusetts primary.
Tomorrow's vote will have no bearing on which candidate will ultimately receive some or all of Vermont's 17 delegates. Delegate selection will take place in local caucuses on April 24. There is no obligation for the caucus results to reflect the outcome of the primary election results.
In 1980 President Carter defeated Sen. Edward M. Kennedy in the March 6 ''beauty contest'' vote in a 3-to-1 landslide. But on April 24, as a result of behind-the-scenes politicking, Senator Kennedy won the caucuses by a 3-to-2 margin.