Declaring that the “Affordable Care Act is here to stay,” President Obama on Thursday urged Americans to ignore Republican misgivings about his signature legislative achievement just five days before the launch of open enrollment in Obamacare.

Unable to shake persistent wariness of his health care reforms, the president insisted that Americans would warm to the new health law once they understand how it works.

“Go check it out for yourself; make up your own mind,” the president said in Largo, Md., just miles from the White House.

Obama added that Republicans weren't worried that his health care overhaul would fail, but that it would actually work.

At one point, the president even accused some in the GOP of calling the Affordable Care Act "worse than the law that let slave owners get their runaway slaves back."

Over the next six months, the administration will look to convince the uninsured to sign up for the most comprehensive overhaul to the health care system since Medicare was created in 1965.

To hear Obama tell it, beginning next week, Americans will easily be able to shop for competitive health plans.

Republicans counter that the federal government and states aren’t prepared to facilitate the massive network of exchanges. The administration already delayed the mandate that employers provide their workers with health insurance or pay a fine, GOP leaders point out.

Obama on Thursday looked to frame his appeal in personal terms, telling the friendly Maryland audience about a family trip to the hospital when he was just a young father.

“We were fortunate enough to have good health insurance,” Obama said. “I remember looking around the emergency room and thinking, ‘what about the parents that aren’t that lucky?’"

As Obama championed his health care reforms, congressional Republicans moved ahead with a plan that would link an increase in the nation’s debt ceiling with a one-year delay in Obamacare.

And Sen. Joe Manchin, D-W.Va., came out in support of delaying the individual mandate, giving Republicans ammunition in their anti-Obamacare crusade.

The president reiterated on Thursday that he would not negotiate around increasing the nation’s borrowing capacity, saying it would be irresponsible for Republicans to risk default and another downgrade of the U.S. credit rating.

The biggest question Obama has to answer for skeptical observers is whether the costs of their health plans would skyrocket under the federal blueprint.

A new Bloomberg poll released late Wednesday found that 60 percent of respondents believe Obamacare will increase medical-care costs. One in three Americans said they would be worse off than they were before the law was implemented.

The president argued that such fears are overblown.

“Think about it, good health insurance for the price of your cellphone bill,” Obama said in an appeal to younger Americans.

For Obamacare to succeed, younger, healthier people must enroll or premiums will soar for older, sicker Americans.

However, Republicans on Thursday were unmoved by the president’s latest health care sales pitch.

“It must be frustrating for the president that folks seem to keep tuning out all the happy talk anyway,” Senate Minority Leader Mitch McConnell, R-Ky., said. “Well, it's not hard to see, frankly, why Americans aren't buying the spin.”