Sen. Howard Baker, back in Washington after a severe drubbing in two New England primaries, said last night that he will meet with his staff today to decide on the future course of his presidential campaign.

The Tennessee Republican finished fourth in Massachusetts and Vermont, after earlier coming in third in the Iowa caucuses and the New Hampshire primary. Asked whether he plans to stay in the race, he said, "I don't know."

Before yesterday's returns were in, Baker cut his paid campaign staff by 20 percent and replaced his two national political directors, Andy Lawrence and Bill Tucker, with Dick Redman, an aide to Iowa Gov. Robert Ray who ran the Baker campaign in Iowa.

In addition, Baker's campaign press secretary, Tom Griscom, said he would return today to Baker's Senate staff.

In a brief and subdued press conference at National Airport last night, Baker put the best face he could on the primary results, saying they were "good for John Anderson and bad for Howard Baker and bad for Ronald Reagan and George Bush."

Just back from South Carolina, Baker said he would remain in that state's primary on Saturday. Griscom said it is also "still the plan" to stay in the March 18 Illinois primary. But Baker did not mention plans for other primaries.

Baker said this is "the most volatile campaign I have ever seen -- that is the one thing you have got to say." Then he walked slowly out to a waiting Chrysler and looked around, blinking wearily in the glare of the television lights. "Now if somebody will produce a bag for me," he said, "we'll be ready to go."