Think about poor New Jersey. Here it sits, hemmed in by the ocean to the east, dominated by New York in the north, squeezed by Philadelphia in the south. It is thought of as a place to drive through on the way to someplace else.

On Tuesday, the last day in the 1980 presidential primary calendar, there will be an election here, but the action, as usual, will be someplace else. It will be mostly in Ohio, where President Carter and his campaign strategists decided they could most easily puncture the claim of Sen. Edward M. Kennedy (D-Mass.) that a massive industrial state revolt is brewing against the president. It will also be in California, which is far larger than New Jersey and also has better weather.

New Jersey knows where it stands in the presidential politics in 1980.

"We've heard so much about Iowa, New Hampshire and all the rest, that it kind of makes people at the tail-end of the process somewhat dulled," said Peter Curtin, exective director of the state Democratic Party.

George Bush's withdrawal from the race eliminated the last vestige of interest in the Republican campaign. On the Democratic side, Curtin is among the many people here who predict a low turnout Tuesday and a tight contest between Kennedy and Carter.

The last published poll, by the Gannett newspapers, showed the president slightly ahead. But Carter campaign aides say their polls show Kennedy out front by a slim margin. Neither side is predicting victory.

There are 113 delegates at stake in the New Jersey primary, the eighth largest delegation to the Democractic National Convention. But because New Jersey must share the spotlight with the larger states of Ohio and California on the last primary day of the year, the campaign here, for the most part, has been overlooked and underfunded.

The Carter national strategy for the final round of primaries has been simple -- prevent Kennedy from sweeping the three big state primaries on Tuesday, thereby denying him the chance to claim there has been a fundamental shift in sentiment in Democratic voters.

The New Jersey effort has also been cramped for resources because the Carter campaign is nearing the national spending limit for primaries. Barry Brendel, Carter's New Jersey campaign director, has had to try to organize the state on a budget of $25,000.

Finally, New Jersey suffers from the peculiarity of not having a commercial VHF television station. Three-fourths of the state is in the expensive New York media market. The rest of the state is reached by Philadelphia television stations. As a result, Curtin noted, campaigning in New Jersey by television "is not cost effective."

Nevertheless, the president's strategists last week decided to spend $90,000 on a series of last-minute television commercials, much to the relief of Brendel, who is worried about the "low visibility" of the Carter campaign here.

Carter has enjoyed here, as in most other states, the backing of the state's Democratic establishment, beginning with Gov. Brendan T. Byrne. He also has the support of a majority of the county Democratic chairmen and the backing of Newark Mayor Kenneth Gibson and other prominent black leaders.

However, the Carter campaign's concern over New Jersey's large black vote is evidenced by the scheduling of a final appearance with Gibson on Monday by Rosalynn Carter.

The Kennedy campaign is located half a block from the Carter New Jersey headquarters on Morris Avenue here, an unlikely spot chosen solely because of its easy access to the New Jersey Turnpike and the Garden State Parkway.

John Sasso, Kennedy's state coordinator, will not discuss campaign budget figures. But he will discuss what he calls "the Kennedy tradition" in New Jersey. More than half of New Jersey's Democratic voters are Catholic, Sasso noted, and the hope is that they will vote like the Catholics in New York and Connecticut -- which Kennedy carried -- rather than the Catholic voters of midwestern states where he lost.

"Voters here now know Kennedy better than they do in the Midwest," Sasso said. "They believe he has represented the economic interests of the industialized Northwest. In places like Iowa and Illinois, everybody knew the Kennedy name, but they did not know what Ted Kennedy has worked on and represented for 17 years in the Senate."

In half a dozen campaign days here in the last month, Kennedy has hammered hard on Carter's economic policies and the recession, which Sasso says is of deep concern to New Jersey voters. At the moment, however, the state unemployment rate is lower than the national average and it dipped slightly last month.

For Kennedy, New Jersey represents a fleeting last chance to claim that he is the choice of voters in traditional Democratic strongholds in the urban areas of the Northeast. It is less important to the president, who is confident of having more than enough delegates to gain the nomination regardless of the results here.

"We did better in the May primaries than anyone could have conceived," said one of the president's strategists. "Now what we're doing is looking for a little gravy."