WASHINGTON >> Lawmakers are not usually eager to get back to Washington after a weekend in their districts, especially during campaign season. But Rep. Michele Bachmann boarded a flight from Minnesota on Sunday night — even though the House will not meet until Tuesday — to make sure she would not miss the Washington moment she has been excitedly anticipating, the Supreme Court ruling on President Barack Obama’s health care law.

“The decision on Obamacare goes well beyond health care,” Bachmann, a Republican and a vocal opponent of the law, wrote in an email. It “will determine whether or not the court believes the government has a right to mandate that Americans buy a product or service, a direct impact on our freedom and liberty.”

The impending heath care ruling by the Supreme Court has become this city’s O.J. Simpson verdict crossed with a papal conclave — polarizing, maddeningly unpredictable and shrouded in mysterious signaling. The ruling is expected to come this week, either shortly after 10 a.m. Monday, the last scheduled day of the term, or on an extra day later in the week.

For members of Congress, health care lobbyists, campaign officials and thousands of lawyers (and the thousands more who have just taken the LSATs) who populate the squat office buildings across the district, the wait for the fate of the health care law has become all consuming.

They constantly check Scotusblog, a website devoted to the doings of the court. They play Health Reform Bracketology, a website where they can choose among various possible outcomes. They fret, write multiple versions of news releases and fret some more, wondering when the decision will be revealed.

For some it is mere wonkery, but for many more the decision means something concrete: ideology, money and an electoral wedge. Coming at the crest of a contentious presidential campaign, it will be the beginning of the end of one of the most divisive policy battles in decades, one that helped set off the Tea Party movement and became the central conflict in the raging political war between Republicans and Democrats over the proper role and scope of government.

“This is such high drama,” said Andrew Rosenberg, a partner specializing in health care at Thorn Run Partners, a government relations firm. “Because you have this decision that everybody knows was made months ago in a town that notoriously does not keep secrets well with such unprecedented implications for one-sixth of the economy.”

The frenzy is just as palpable on the left as it is on the right.

For Karen Davenport, the director of health policy at the National Women’s Law Center, it is “the first thing I think about when I get up in the morning” and the topic she spends most of her day talking about with colleagues. Sitting in a meeting Thursday, one of several days the court could have ruled on the health care law, “I was watching my iPhone the whole time,” she said. “You can’t help but have that hamster in the wheel in your head over the various outcomes. It’s a very anxious time.”

The two most engaged groups are probably those made up of people who have spent their entire professional lives working on health care policy and House Republicans who have devoted much of the 112th Congress to trying to overturn or defunding various aspects of the law.

Bachmann instructed her staff to reserve space at the House triangle — a spot of green outside the House side of the Capitol — where she plans to hold a news conference within 90 minutes of the decision. After that, she plans to head to the Supreme Court to join Tea Party groups who are expected to gather there.

The press offices of most congressional Republicans are busy preparing three or four versions of news releases they hope to send out moments after the decision is announced, along with missives for their constituents.

“We’re working on the language now,” said Rep. Martha Roby, R-Ala., who has given several interviews on the topic with reporters back home. “It’s certainly on the hearts and minds of everybody.”

Richard Mourdock, the Republican nominee for the Senate from Indiana, had his recorded versions of a response spread across the Internet last week.

For the past eight weeks, members of Speaker John A. Boehner’s staff have met with their counterparts from the office of Sen. Mitch McConnell of Kentucky, the minority leader, to devise a game plan on how to respond. Over the past few weeks, representatives from Mitt Romney’s presidential campaign have been brought into the loop as well. No matter the outcome, Republicans are expected to push forward with legislation to repeal the law.

Boehner, however, cautioned House Republicans in a memorandum last week not to seem too joyous if all or part of the law was struck down.

“We will not celebrate at a time when millions of our fellow Americans remain out of work, the national debt has exceeded the size of our nation’s economy, health costs continue to rise, and small businesses are struggling to hire,” he wrote. This may reflect a growing chasm between Republicans who want to push for measures that would uphold popular parts of the law and those who prefer to let the market rule.

In a nothing-to-see-here contrast, Democrats are coordinating far more loosely, according to several media operatives on Capitol Hill, under the notion that they expect the law to be upheld. A spokesman for the White House declined to discuss post-decision plans.

At a Democratic caucus meeting last week, Sen. Harry Reid of Nevada, the majority leader, was peppered with questions about the ruling from anxious senators, whom he told there should be less fretting about things they cannot control, an attendee said.

Scotusblog — the TMZ of the legal world, which the court has not officially recognized — will not be caught unprepared. The site has rewritten its software and moved its popular live blog to a new dedicated server to accommodate the expected traffic, which is already rising fast.

“Our lives are completely different for this brief, fleeting solar flare,” said Tom Goldstein, who publishes the blog. The closest analogy was a guns case that attracted 250,000 visitors, he said; he is expecting eight to 10 times as many readers on the day of the decision.

The live blog will have seven people working full time, compared with the normal two. “We will keep the live blog up so people don’t have to refresh,” he said.

For health care advocates and others who work in the world of health care policy, it is a bit like waiting for a baby to arrive.

“For advocates, it’s so weird,” said Emily J. Holubowich, executive director of the Coalition for Health Funding. “When there is something on the Hill, you can advocate. But in absence of anything productive to do, we follow Scotusblog, play Bracketology and do office pools while we wait. Anyone who thinks they know what’s actually happening is full of it.”

© 2012 The New York Times Company