Washington goes 'Hog' wild over its Redskins . . .

''I got three kinds of hats,'' says Baron the street vendor. ''This gold kind here, these burgundy ones, and the camouflage caps that say 'Riggo's Rangers.' I got Redskin scarves and two models of pennants. I got T-shirts that say 'Love Them Hogs' and 'The Fun Bunch.' ''

He peers up at the snowstorm that is threatening to bury his Connecticut Avenue table. ''Business has been great,'' he says, ''but I can't take this snow. I'm gettin' out of here.''

Signs of Redskin mania are now everywhere in Washington, from bus passengers wearing giant foam hands that say ''We're #1'' to banks dressed in ''Hail to the Redskins'' banners.

Morning disc jockeys play the Redskin fight song every five minutes. Political humorist Mark Russell, appearing Tuesday at a public employees benefit , walked onstage waving a Super Bowl pennant and wearing a pink hog nose, in honor of the Redskins' offensive line, nicknamed the Hogs.

The Redskins are even becoming a political force. Fullback John Riggins - who in action resembles a low-flying 747 - has sent President Reagan an autographed picture, inscribed ''You've got my vote.'' Reports that Walter Mondale is trying for quarterback Joe Theismann's endorsement remain unconfirmed.

Washington has always been quick to clasp a winner to its bosom, be it an athlete or a politician. Victorious in last year's Super Bowl, poised for another try this Sunday, the city's football team right now has the aura of a champion.

The possibility of defeat is simply not discussed. Rather, conversation centers on what the celebration in Georgetown will be like after the game. In the wake of last year's Super Bowl victory, traffic there was tied up for hours by happy fans. At least one resident is worried that if he's not home by the fourth quarter, he won't be able to reach his house till Monday.