Joseph Campos of Cambridge says he's a true patriot. Nobody tells him how to vote. He'd never think of joining a party.

But he always votes Republican.

"Democrats waste the people's money," Campos says. "They enjoy it too."

There wasn't any rain to keep Cambridge voters indoors yesterday. But voters without Campos' sense of mission could find few hotly contested races to entice them from their homes.

In one of the nation's most liberal cities, most voters looked on the general election as a formality for winners of September's Democratic primaries.

As the polls closed yesterday, Massachussetts voter turnout inched up toward 50 percent--higher than the 38 percent Democratic Secretary of State Michael Connolly had predicted--but not high enough to keep Election Day '86 from being one of the least energetic in the commonwealth's history.

There wasn't much question that the political debut of Democrate Joseph P. Kennedy II would be successful.

Several said they wondered if the outcome had been fated a generation earlier--when his uncle, John F. Kennedy '40, gave up the Eighth District seat to move on to other things.

Kennedy stalwarts turned out en masse to send the youngest of the Kennedy political clan to the seat being vacated by retiring House Speaker Thomas P. "Tip" O'Neill Jr. with a stylish 71 to 21 percent victory over Republican candidate Clack C. Abt.

Delores Carey, 53, toted a "Kennedy for Congress" placard outside the Cambridge Rindge and Latin High School to make sure ballot-casters "won't forget to vote for Joe."

"We want to send Joe to Congress with a strong support from the people," Carey said.

In Cambridge polling places, voters contributed to the tremendous victory of Democrat Michael S. Dukakis, the handiest Massachussetts gubernatorial victory since 1918.

"We owed him," said one Cambridge supporter of the re-elected Governor, referring to Massachusetts' recent strong economy.