Both Democrats and Republicans say that a clean spending measure -- with no Obamacare amendments, as urged by the president and his allies -- would pass the House with support from the Democratic minority and moderate Republicans.
Veteran GOP Sen. John McCain of Arizona noted that any attempt to repeal Obamacare was going to fail because of Obama's veto, which would require a two-thirds majority in the Senate to overcome. And GOP Rep. Peter King of New York said the problem is tea party conservatives tied to Sen. Ted Cruz of Texas who "really care about nothing but their own agenda" driving the Republican approach in the House.
"We have people in the conference, I believe, who'd be just as happy to have the government shut down," said King, who has been among the Republican legislators pushing for a "clean" funding bill without anti-Obamacare provisions. "They live in these narrow echo chambers. They listen to themselves and their tea party friends. That keeps them going, forgetting that the rest of the country thinks we're crazy."
However, Boehner has succumbed to pressure from the tea party right to avoid a vote that would pass something without causing some harm to the health care reforms.
Speaking in the early minutes of the shutdown, the Ohio Republican insisted the House voted "to keep the government open" and assure "fairness for all Americans under Obamacare" -- then walked away from the podium.
White House spokesman Jay Carney told CNN such intransigence is the root of the shutdown, noting that conservative Republicans such as Rokita are the only ones pushing a political agenda for meeting the congressional responsibility of passing a budget.
Amid the finger-wagging and fulminating, major components of the new health insurance law went into effect on schedule on Tuesday.
"The Affordable Care Act is moving forward. You can't shut it down," said a post on Barack Obama's verified Twitter feed.
A blow to the economy
The shutdown of the government -- the country's largest employer -- isn't happening all at once.
Federal employees who are considered essential will continue working. Those deemed non-essential -- up to 800,000 -- could be furloughed, unsure when they'll be able to work or get paid again.
The shutdown could cost the still-struggling U.S. economy about $1 billion a week in pay lost by furloughed federal workers. And that's only the tip of the iceberg.
While many agencies have reserve funds and contingency plans that would give them some short-term leeway, the economic effect would snowball as the shutdown continued.
The total economic impact is likely to be at least 10 times greater than the simple calculation of lost wages of federal workers, said Brian Kessler, economist with Moody's Analytics. His firm estimates that a three- to four-week shutdown would cost the economy about $55 billion.
Initial market reaction around the world indicated little serious concern for now. In New York, all the major indexes were higher on Tuesday after closing lower the day before. World markets also rose, while the dollar slipped against other major currencies.
Troops, congressional paychecks safe
Although much of the federal workforce will go without pay, checks will keep coming to the 533 current members of Congress. The president too will get paid. His salary -- $400,000 -- is considered mandatory spending.
Some members of Congress and government officials have said they will donate their salary to charity during a shutdown.
Members of the military will also get paid -- thanks to Congress, which unanimously managed to come together to pass a bill that Obama signed.
But it's uncertain how the shutdown will affect veterans, including the 3.3 million who are disabled. If the shutdown stretches into late October, the Veterans Affairs Department could have to halt disability and pension checks for elderly and ill veterans.
"That's what they need to pay rent, to pay food," said Tom Tarantino of the Iraq and Afghanistan Veterans of America. "It's not their total income, but it is a significant part of it."
According to a CNN/ORC poll, 68% of Americans think shutting down the government for even a few days is a bad idea, while 27% think it's a good idea.
And it appears most Americans would blame congressional Republicans for a shutdown: Sixty-nine percent said they agreed with the statement that the party's elected officials were acting like "spoiled children."
Democrats, however, weren't far behind: Fifty-eight percent of respondents said they, too, were acting like spoiled kids.