President Barack Obama castigated House tea party members on Tuesday for shutting down the government over an "ideological crusade" on health-care reform.
Speaking from the White House Rose Garden on the first day of the partial government shutdown, Obama said the longer the shutdown continues, the worse the impact will be.
The shutdown, the first in 17 years, kept some 800,000 federal workers home. Barricades sprang up early Tuesday at the Lincoln Memorial and other monuments, and the National Park Service was turning off 45 fountains around the capital city. National parks from Acadia in Maine to Denali in Alaska followed suit, as did many federal workplaces.
The president said Republicans should not be able to hold the entire economy "hostage." He urged them to reopen the government quickly and allow furloughed federal employees to go back to work.
"This Republican shut down did not have to happen ... but I want every American to understand why it did happen," he said. "Republicans in the House of Representatives refused to fund the government unless we defunded and dismantled the Affordable Care Act. They've shut down the government over an ideological crusade to deny affordable health insurance to millions of Americans. In other words, they demanded ransom just for doing their job."
(Read more: 800,000 out of work as government shuts down)
The government shut down because Congress did not pass a funding bill ahead of Monday's midnight deadline for the end of the 2013 fiscal year. The tea party insisted on a delay in funding for Obama's Affordable Care Act, which opened as scheduled Tuesday despite the government shutdown.
Republican Sen. John Cornyn of Texas said GOP lawmakers were listening to constituents who want to "stop the runaway train called the federal government." Their message, he said, is "Stay strong."
In the House, conservative Rep. Marsha Blackburn predicted the standoff might drag on for days if Obama and Senate Democrats refused to bargain. "People are going to realize they can live with a lot less government," Blackburn, R-Tenn., told Fox News.
Obama also addressed the looming debt ceiling. If Congress does not lifting the debt ceiling, he said it would be worse than a government shutdown—mentioning that it would result in an economic shutdown.
The debt ceiling will be reached on Oct. 17.
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Obama said the opening of of registration for the new health exchanges under Obamacare was a "historic day."
"This is life-or-death stuff," Obama said, adding that tens of thousands of Americans die each year for lack of health insurance, and others go bankrupt. "Today we begin to free millions of our fellow Americans from that fear."
The president spoke alongside a group of citizens who plan to purchase insurance through the system.
His message to Americans is that the health care exchanges will not shut down since they are previously funded.
Obama accused Republicans of making the concept of keeping people uninsured "the centerpiece of their agenda."
"We know the longer this shutdown continues the worst the effects it will be," Obama said. "More families will be hurt, more businesses will be harmed. Again, I urge House Republicans to re-open the government, restart the services that Americans depend on, and allow the public servants who have been sent home to return to work."
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—By CNBC.com with AP.