Fred Crickenberger, a retired federal worker living in the working-class Cabin John section of Montgomery County, doesn't care too much for Republicans. He isn't fond of President Reagan, he says inflation "really hurts" and he's worried about his federal pension.

So Crickenberger's first question to the House of Delegates candidate visiting his door the other day was blunt: "Are you a Republican or a Democrat?"

Del. Constance Morella had heard the question before during her afternoon of door-to-door shoe-leathering in the tiny enclave wedged between MacArthur Boulevard and the Potomac River.

"I'm a Republican who couldn't be elected without the support of Democrats," she said, repeating her standard campaign line.

Being a Republican in Montgomery County isn't easy, even for a Republican in the liberal tradition of Sen. Charles McC. Mathias and former Rep. Gilbert Gude. In precinct 7-3, which includes Cabin John and the liberal stronghold of Bannockburn, being a Republican is especially difficult. The precinct's registration is 62 percent Democratic, 26 percent Republican and 11 percent independent.

This year, an increasingly unpopular Republican president and a troubled national economy have given local Republican candidates an added burden.

State Sen. Howard A. Denis, who also represents the 16th legislative district, called it "the razor's edge" that all GOP candidates must traverse--running as liberal Republicans in predominantly Democratic districts, while trying to distance themselves from unpopular Republican policies.

"As a liberal Republican, Connie has got to set herself aside a little bit from the policies of Reagan," said county GOP chairman Paul Clark.

Some of those policies worry the federal workers--civil servants such as Transportation Department worker Joseph Innes.

"I'm concerned primarily about the equity and laws that affect federal workers," Innes said when asked about his top list of concerns. "The one I'm really concerned about is this civil service reorganization. It's becoming highly politicized. Where we had 10 or 15 percent political appointees, the new system allows 25 percent."

Another Bannockburn resident, Priscilla Rice, said her biggest concern was Social Security: "Just keep the money flowing to us old folks," she said.

"My kids are worried about all the Social Security they're paying in. They want to know if it'll be there when they get older. I just hope to God so."

Morella's party affiliation is not mentioned in the four-page newsletter she leaves at each household.

Her party is mentioned in an accompanying handout--a copy of an "admittedly favorable" article reprinted from the Potomac Almanac and written by a Democrat.

And in talking to people, she mentions her party only when asked.

"If they ask, I say 'yes, I'm a Republican.' I want them to know it, but I don't flaunt it," she said.

"You're a Republican," mused Marilyn Lane, a Bannockburn resident glancing at the reprinted article handed to her at poolside.

"I'm a Republican who can't win without the votes of Democrats," Morella said quickly. "I like to think people in this county vote for individuals."

"Being a Republican is like being a masochist," Morella said later, pacing briskly from house to house through a neighborhood of posh stone mansions.

"If the economy doesn't really get better, and if people's concerns aren't assuaged by some real improvements in the tangible indicators, it could be a difficult year for Republicans." She paused, adding, "This is a difficult time for Republicans."

Difficult, yes. But no one is predicting a Republican wipeout similar to the Watergate backlash of 1974. Morella ran that year and lost, as did every other Republican candidate for the legislature from Montgomery County.

"She spent the next four years working," said GOP chairman Clark. In her 1978 campaign, Morella, then chairwoman of the Montgomery College English department, was able to overcome the Democratic registration edge with a strong organization and appeals to the district's highly educated and independent-minded voters.

She was helped that year by a weak Democratic incumbent.

Only once that year, Morella said, did she find a woman who said: "Oh, this is a good neighborhood--we vote a straight Democratic ticket."

Morella was the top vote-getter in her district in that election.

This time, the issues will be economic. "People will vote their pocketbooks," said Morella's campaign aide and walking companion, Marian Chapman. "It all depends on the economy."

It is a difficulty that Democrats hope to exploit. County Democratic Chairman Stanton J. Gildenhorn has gleefully called Reagan "the albatross that will be around the necks of all Republican candidates."

Democratic candidate Abbe D. Lowell, a lawyer waging an aggressive fight for a delegate's seat in Morella's district, has accused her of failing to lobby the Republican White House for the concerns of federal workers.

And even Morella's departure recently from the congressional campaign committee of combative Marian Greenblatt provoked the two incumbent Democratic delegates from the 16th, Nancy Kopp and Marilyn Goldwater, to fire off letters to newspapers questioning why she had joined the Greenblatt campaign in the first place.

Morella wasn't fazed.

"I knew they were going to try to hang that on me," she said. "But I'm convinced, negative campaigns will eventually backfire."