WASHINGTON (AP) - There are suggestions from leaders in both parties that the partial government shutdown could last for weeks.
President Barack Obama said Republicans brought about the shutdown as part of an "ideological crusade" to wipe out his health care law. House Speaker John Boehner, writing in USA Today, says Democrats "slammed the door on reopening the government" by refusing to negotiate.
The standoff that partially shut down the U.S. government persisted with no sign of a breakthrough Tuesday, as the Democratic-led Senate rejected a House Republican effort to negotiate a solution to a dispute over the health care overhaul.
About 800,000 employees - about a third of the federal workforce - are being forced off the job in the first government shutdown in 17 years, suspending most nonessential federal programs and services. People classified as essential employees - such as air traffic controllers, Border Patrol agents and most food inspectors - will continue to work.
In a 54-46 party-line vote, the Senate turned aside a House request to name negotiators to a conference to resolve differences. The shutdown began when Congress missed a midnight deadline Monday to pass temporary funding bill, stalled by conservative efforts to push through a delay in President Barack Obama's health law.
Senate Majority Leader Harry Reid said he would not negotiate as long as Republicans were holding up a straightforward spending bill to keep the government operating.
It wasn't clear how long the impasse would last. The Senate vote marked the fourth time during this fight that it has rejected House Republican proposals.
Obama said House Republicans have shut down the government over an "ideological crusade" against his health care law and warned the longer it continues the worse the impact will be.
Speaking at the White House Rose Garden, the president said Republicans should not be able to hold the entire economy "hostage." He told federal workers in an email earlier that he hopes Washington quickly resolves the shutdown, which he called "completely preventable."
White House communications director Jennifer Palmieri told MSNBC that the administration is open to changes in the health care law in future negotiations, but not as part of passing a budget bill. She compared that to negotiating with "a gun pointed to your head."
Stock markets around the world reacted resiliently, with analysts saying significant damage to the U.S. economy was unlikely unless the shutdown lasted more than a few days. U.S. stocks edged higher Tuesday, while European stocks mostly recovered after falling the day before the shutdown deadline. Asian stocks were mixed.
The stalemate pits Democrats against a core of conservative small-government activists who have mounted a campaign to seize the must-do budget measure in an effort to dismantle the 2010 health care reform, which is intended to provide coverage for the millions of Americans now uninsured.
In the House, conservative Rep. Marsha Blackburn predicted the standoff would drag for several days. "People are going to realize they can live with a lot less government," she told Fox News.
Republicans passionately oppose the plan they have dubbed "Obamacare" as wasteful and restricting freedom by requiring most Americans to have health insurance.
A key part of the health law was taking effect Tuesday, unaffected by the shutdown. Enrollment opened for millions of people shopping for medical insurance.
National parks, museums in Washington and agencies like NASA and the Environmental Protection Agency nearly closed. The National Zoo in Washington closed to visitors and turned off the popular panda cam that had showed off a weeks-old cub.
Pentagon and administration lawyers were looking for ways to expand the number of Defense Department civilians who are exempt from furloughs, amid worries that that the shutdown is damaging U.S. credibility among its international allies, Defense Secretary Chuck Hagel said Tuesday.
Until now, such temporary spending bills have been routinely passed with bipartisan support, ever since a pair of unpopular shutdowns in the winter of 1995-1996 severely damaged Republican election prospects and revived then-President Bill Clinton's political standing.
The Republican leader of the House, Speaker John Boehner, said he didn't want a government shutdown, but he insisted that the health care law "is having a devastating impact. ... Something has to be done."
Republican leaders have voiced reservations about the effort and many lawmakers predicted it wouldn't work, fearing the public will blame their party for the shutdown. But individual Republican House members may face a greater risk by embracing a compromise. Many represent heavily partisan congressional districts, and voters in Republican primaries have ousted lawmakers they see as too moderate.
Federal workers were told to report to their jobs for a half-day but to perform only shutdown tasks like changing email greetings.
The White House was operating with a skeletal staff, including household workers taking care of the first family's residence and presidential aides working in the West Wing. White House officials were discussing whether Obama should change plans for a trip to Asia scheduled to begin Saturday.
Lawmakers and the president were still getting paid, however, at a rate totaling more than $250,000 per day. That frustrated some Americans worried about the ripple effects of the shutdown.
Barbara Haxton, executive director of Ohio Head Start Association, said her program for poor preschoolers would be in jeopardy if the shutdown lasted more than two weeks.
"These are the poorest of the poor children," Haxton said. "And our congressman still gets his paycheck."
The State Department will continue processing passports and visas because that service is financed through fees. Embassies and consulates overseas will continue to provide services.
Looming ahead is a potentially more dangerous fight: Republicans are likely to take up the health care fight again when Congress must pass a measure to increase the nation's borrowing cap. The U.S. risks a market-rattling, first-ever default on its obligations if Congress fails to raise that limit.