If preparations for election night are a sign, it looks like Washington’s midterm madness is more of a low-grade fever than a full-blown affliction.

The mood is a little more subdued this year. Nationwide, unemployment is rampant and the economy is sputtering. Even Republicans, who expect to make big gains at the polls tonight, are taking pains to avoid looking like they’re popping champagne corks as voters fret about their own jobs.

And these are less-sexy midterms, not a presidential year ‘ and certainly not one with the added giddiness of the history-making vote in 2008.

Still, election night in Washington is a relatively big deal. If Washington is a company town, think of election night as the office holiday party.

At the Capital Grille, the white-tableclothed, wood-paneled watering hole on Pennsylvania Avenue, patrons are usually relatively subdued. A hearty guffaw following a golfing joke might be the loudest noise in the room during a normal dinner hour.

But managing partner Adam Shapiro said he’s expecting a lively and large crowd tonight. The restaurant is fully staffed, which isn’t typical for a Tuesday night when Congress is out of session, he said. There are extra valets to handle the traffic, and Shapiro rented two TVs to supplement the two already perched above the bar, all the better for patrons to watch the returns.

‘I’ve been sensing anticipation from customers on both sides of the aisle,’ he said.

At Schneider’s of Capitol Hill, the liquor and wine store just steps away from Senate office buildings, co-owner Josh Genderson said sparkling wine is suddenly a big seller. Last week, sales began to climb, which is early for holiday stocking-up, he said. ‘The holiday rush seems to have come early,’ he said. ‘Can I say for sure that it’s because of election night? Not really, but it seems likely.’

At the old-school Salon Jean-Paul, which tends to the coiffures of many A-list political and media clients, there are signs that this election night has been one to dye for.

Co-owner Glenn Irving said he’s booked more clients than usual in the days leading up to the election. And there will be fewer dark roots among the salon’s stable of media, lobbying and political clientele: Root touch-ups (all the better for high-definition TV appearances) have been the most requested service.

‘Usually, people will stretch it just a few more weeks, and we’ll see a lot of color work right before Thanksgiving,’ he said. ‘But we’re busier this year, we’re doing more color than usual, and the only thing that’s different is the election.’

The apparatus that supports official Washington ‘ the busboys and taxi drivers, the hair stylists and valets ‘ will be catering not just to the talking heads at cable news bureaus and the Congressional staffers not out helping candidates in far-flung districts. They’ll be waiting on the regular folk in Washington, where even people whose livelihoods don’t directly depend on Congress are obsessive about politics.

Lynne Breaux, the president of the Restaurant Association Metropolitan Washington, said the crowds filling bars and restaurants around Washington tonight will mostly just be locals who want to share the experience of a potentially game-changing election night.

‘People just want to be in a communal environment on a night like this,’ she said, whether that means drowning sorrows in booze or toasting to a new regime. ‘We really are a bunch of political junkies.’

And while some businesses are preparing for a busy night, there are signs that midterm madness is hardly an epidemic.

Chuck Lemine, whose business, Capitol Sedan and Limousine Service, ferries VIPs around town in a fleet of about 20 Town Cars and limousines, isn’t expecting a busy night.

‘There aren’t that many bookings for Nov. 2,’ he said. ‘Maybe there will be people booking last-minute, but it doesn’t look like it.’

And the excitement over election night apparently hasn’t reached American Spirit, the shop at Union Station where a beaming Sarah Palin cutout looms behind cutouts of President Barack Obama and first lady Michelle Obama.

Manager Linda Williams said the midterms haven’t generated much excitement, or demand. ‘We haven’t gotten anything special in,’ she said. ‘People haven’t seemed to want it.’