They come every morning, thousands of them, by Metro bus and motorbike and carpool. They sweep down the long curving sidewalks to the Silver Spring Metro station in great waves, clutching their purses and briefcases, eyes fixed straight ahead, minds usually far away.

Ten months of the year, they are rushed, anonymous commuter-herds. Since early September, though, they have been the discerning voters of Montgomery County. And politicians are in love with them.

"I can meet more people here in an hour outside the station than I can in two weeks traveling around the country," said Bob Brennan as he campaigned for the Montgomery County Council outside the station one morning last week. "The best thing is, they'll read your literature while they are sitting on the train - instead of add one politicking.

The Silver Spring Metro station has become the Mecca of Montgomery politicians, the voter-rich shrine where all must journey - the earlier in the morning, the better - to demonstrate their dedication and worthiness for office. "It's our factory gate," says congressional candidate Mike Barnes.

Barnes has been there four mornings, and held a press conference there last month. Charles Gilchrist, the Democratic executive candidate, was there Tuesday with Sen. Paul Sarbanes. His opponent, Richmond M. (Max) Keeney, and lieutenant governor-hopeful Sam Bogley planned to be there today.

Mike Gudis, a county council candidate, has campaigned at Silver Spring 13 times. "It gets pretty crowded out there sometimes," he says. "But it's usually Democrats who are there early in the morning. Maybe Republicans don't realize the value of it."

Democrats do seem to compete for earlier and earlier arrivals at the station. According to Metro's figures, the peak morning periods are between 7:30 and 8, when an average of 1,588 commuters arrive at the station, and 3 and 8:30, when an average of 1,428 show up.

Barnes, however, insists on arriving at 5:59, when the first train leaves. "Running for office takes dedication," he says, solemnly. "And people recognize it. I've had people tell me that they'll vote for anybody who shows up this early in the morning."

"There aren't many other things you can be doing at that time," explains Gudis, who usually sleeps in and arrives at the station at 6:30. "Not everyone can be a candidate. It's a rough chore."

Gudis and barnes are the hardliners on one side of the great morning evening debate. Some candidates prefer the harried commuter on the way to work; others like the exhausted comnuter waiting for a bus on the way home.

It is an issue that could decide at least two elections. "People are in a rush to get home in the evening," said Barnes. "In the morning, if they don't see their train coming, they're willing to stop and talk."

"In the morning people are too rushed to stop and talk," says Newton I. Steers, Barnes' opponent in the 8th Congressional District. "If you go there in the evening, people are more relaxed and have more time while they're waiting for the buses."

Gilchrist and Keeney are similarly at odds. Keeney has visited Silver Spring only in the morning and, in fact, has developed new tactics to outstrip his competitors. "I meet the buses going to Silver Spring at Montgomery Village," he said. "I catch them before they even get to the Metro station."

Gilchrist says that "on the balance," he prefers the evening at Silver Spring - but he too has a morning ace-in-the-hole.

"I've been going to the Takoma Park station in the morning," he boasted. "That one's kind of a sleeper - there aren't many (politicians) who try that one. I don't have to defer to anyone there."