WASHINGTON (AFP) - With America's budget battles over at least until December, Republicans stepped up attacks against their favourite target "Obamacare" on Tuesday, seizing on technical nightmares to try to delay its rollout.
The Obamacare websites' rocky debut from Oct 1 had been largely obscured by the political clashes in Washington over federal spending and whether to raise the nation's debt ceiling.
On Monday, President Barack Obama signalled a shift in tone to acknowledge problems with the sites Americans should use to sign up for health insurance under the Obamacare exchanges.
And with reports emerging that the exchanges launched despite signs of serious problems during simulations, Republicans - bruised by their failed attempts to dismantle the health care law during the budget fight - appeared eager to pounce on a chastened White House.
"It's unfair to punish people for not purchasing a product that they can't purchase right now because the technology that's in place, the website they're supposed to buy it on - by the president's own admission - is not working," Republican Senator Marco Rubio, a potential 2016 presidential candidate, told CBS News on Tuesday.
Beginning Jan 1, most Americans must have health insurance or pay a fine. But that requirement known as the "individual mandate," in which enrollment of young healthy Americans is seen as helping pay for the broader coverage that would largely help the poor, has been hotly challenged by Republicans for months.
"All I'm calling for is a delay on that requirement, until the General Accounting Office of the United States certifies that the website is up and working and functioning and has been functioning for six consecutive months," Mr Rubio added.
"I think that's a prudent approach." Republican lawmakers have consistently opposed Obamacare, with House Speaker John Boehner insisting that dismantling the law remained a top priority for his party.
Many Republicans were reiterating their Obamacare opposition on Monday on Twitter posts.
Fueling the ire has been a series of embarrassing technical glitches riddling the federal website, where many of the tens of millions of uninsured in the United States have had trouble logging on or securing insurance.
"Even Wyoming's own Insurance Commissioner has been unable to personally register despite trying every day," Senator John Barrasso tweeted.
Many critics see such hurdles as symptomatic of a fatally flawed system.
"I don't think any amount of apologising on the part of the president is going to fix the core problem here, which is (Obamacare) can not and will not work," top Senate Republican Mitch McConnell told Fox News late Monday.
"The government is going to botch this. They've had four years to get ready. It's clear to me that this isn't going to work. It's not fixable." Congressman John Fleming, who is also a physician, mocked Obamacare as a "wealth distribution" system that will not benefit most Americans.
"This is a government takeover of one sixth of the largest economy in the world," he said.
Some lawmakers are targeting the top health official in Mr Obama's cabinet, Health and Human Services Secretary Kathleen Sebelius.
Ms Sebelius is expected to testify next week before the House Energy and Commerce Committee, where she will no doubt be grilled on the systemic failures of the open enrollment process.
"We were told repeatedly that implementation was 'on track,' and it is now time for all those responsible to explain what happened," committee chairman Fred Upton said in a statement.
His fellow Republican committee member Bill Johnson said Monday that Ms Sebelius should resign over the disastrous exchanges rollout.
"Absolutely. It starts at the top," Mr Johnson told Fox News.