Congress is stubbornly deadlocked over the federal budget and ongoing rollout of Obamacare, as a midnight deadline for a government shutdown quickly approaches.
There are no bipartisan negotiations or emergency meetings underway on Capitol Hill, and many lawmakers are convinced that parts of the federal government will soon grind to a halt for the first time in 17 years.
The primary political sticking point remains the Affordable Care Act and its individual insurance exchanges, which are set to go online tomorrow just as the government runs out of cash.
House Republicans have passed a bill to keep the government open, but only if the new provisions of the health care law are delayed by one year. They also want to repeal a tax the law imposes on some medical devices.
Senate Democrats and President Obama say any funding bill that includes changes to Obamacare is dead on arrival. The Senate has passed its own measure to keep the government's lights on and the health care law on track.
Neither side appears willing to compromise to reach middle ground.
"The president is the one saying, 'I will shut down the government if you don't give me everything I want on Obamacare," Sen. Rand Paul, R-Ky., said Sunday on "Face the Nation."
Democrats argue that Republican tactics amount to extortion.
"It is wrong to do a shutdown of government as the leverage to make change," Sen. Tim Kaine, D-Va., told "Fox News Sunday."
The Senate is expected this afternoon to formally reject the latest government funding measure passed by the House early Sunday morning because it includes changes to Obamacare. That would put the ball back in the court of House Speaker John Boehner and Republicans with just hours to go to reach a deal.
One top House Republican says there's still a glimmer of hope.
"We will not shut the government down," House Majority Whip Kevin McCarthy of California said on "Fox News Sunday." "We have to negotiate longer and we will continue to negotiate."
Without a last-minute breakthrough, a partial shutdown will take effect at midnight, closing some government offices and slowing down services.
The biggest impact will be felt by 800,000 "non-essential" federal workers, who will be told not to show up to work and will see their paychecks cut off.
Staffing cutbacks at federal agencies could delay processing of first-time home mortgages, lead to longer airport security lines and limit food safety inspections.
All national parks, forests and monuments, including Yellowstone, the Grand Canyon, the Statue of Liberty and the Smokey Mountains, will be closed.
Processing of new and renewal applications for passports will cease. At border crossings, there will be fewer agents to process travelers and secure checkpoints.
Many military service members, including the more than 1.3 million active duty troops, are considered "essential" and will remain on the job, but they likely won't be getting paychecks until an agreement is reached in Congress.
Still, many government benefits and services will continue during a partial shutdown.
The Social Security Administration will continue to write checks to retirees, and because the Postal Service will stay open, those checks will still get delivered along with everyday bills.