One trouble with politics in the modern metropolis is that it's so doggone dull. If you've been to one candidates' forum in Arlington, one wine-and-cheese reception in Washington's Palisades district, one coffee hour in Prince George's, you've pretty much been to them all.

Joe Alexander does things differently. The incumbent Democratic Fairfax County supervisor's fund-raiser in Franconia on Friday evening was just plain fun.

Picture, if you will, about 500 of the mostly faithful sitting at long paper-covered tables in the fire station's huge social hall, cracking huge mounds of spicy crabs and sipping beer or Cokes as Alexander and other politicians worked the aisles, pumping hands and exchanging small (and not-so-small) talk with voters.

I declined one of those target-sized "Joe Alexander for Supervisor" lapel stick-ons, choosing neutrality in Joe's race with underdog Republican challenger Thomas J. O'Connor for both professional and nonresidency reasons.

But Carmen Turner, the Metro transit system's new and presumably nonpartisan general manager, accepted and wore one. Joe is one of her bosses, as a member of the Metro board.

One who didn't wear a stick-on--it's not recorded whether he was offered one--was Jack Herrity, the Republican chairman of the Fairfax Board of Supervisors, who also is engaged in a reelection campaign. He prowled the aisles with a perpetual scowl. He'd have done better if he looked as cheery as host Joe.

There was a surprise. Virginia's lieutenant governor, Richard Davis, unexpectedly dropped by to give Joe a boost and, one suspects, to buttress his own political ambitions.

There was no platform program, no rah-rah. Just more crabs, more beer, more Coke, more talk. The only amplified announcement was that there was a surplus of crabs that was being offered at bargain prices. I bit. That means spending much of today dealing with a picnic icebox filled to the brim with unpicked crabs.