A federal judge's decision declaring the Affordable Care Act unconstitutional suddenly thrusting the fate of Obamacare back into the political spotlight.

While the decision has no immediate impact on current enrollment or on health plans obtained through the 2010 law, the ruling will likely wind its way up through appeals and could land in front of the U.S. Supreme Court.

And it will will pressure lawmakers and the White House to explain how they plan to protect millions of Americans who risk losing their coverage if the ACA is ultimately struck down.

(SOUNDBITE) (English) U.S. DEMOCRATIC SENATOR AMY KLOBUCHAR, SAYING: "We should be working to improve the Affordable Care Act, not just throw it out and set it on fire." Minnesota Democratic Senator Amy Klobuchar on Sunday telling CBS News that Democrats are ready to push for changes to expand existing programs for the poor and elderly.

(SOUNDBITE) (English) U.S. DEMOCRATIC SENATOR AMY KLOBUCHAR, SAYING: "We need universal health care, and there are many ways to get there.

That is one of them.

The other is a t least expand Medicare to age 55.

There's a number of bills, that I'm part of, including allowing the expansion of Medicaid, which is something I think we're not talking enough about." (SOUNDBITE) (English) U.S. REPUBLICAN SENATOR JOHN BARASSO, SAYING: "I think government never does big things really well, I'm for more of a step-by-step, and I want to start with a first step of people with pre-existing conditions." Republican Senator John Barasso saying he favored a more incremental approach to shore up coverage.

(SOUNDBITE) (English) U.S. REPUBLICAN SENATOR JOHN BARASSO, SAYING: "What we're seeing right now from the Democrat side, and you see, whether it's Bernie Sanders or so many of the Democrat candidates for president in 2020, they're talking about a program of a complete government takeover of healthcare with increased taxes and fewer choices and longer lines." The healthcare debate risks putting Republicans in a difficult position.

Most in the party have attacked and derided the Affordable Care Act even as its provisions and benefits, such as protections for pre-existing conditions, grew popular.

(SOUNDBITE) (English) U.S. PRESIDENT DONALD TRUMP, SAYING (SATURDAY): "It was a big ruling.

A great ruling for our country." U.S. President Donald Trump on Saturday hailing Friday's ruling, and promising to deliver a bipartisan fix for healthcare.

(SOUNDBITE) (English) U.S. PRESIDENT DONALD TRUMP, SAYING (SATURDAY): "We will get great, great healthcare for our people.

We'll have to sit down with the Democrats to do it but I'm sure they want to do it also." But Trump was unable to get his own party to agree on an Obamacare replacement during the two years Republicans held complete control of Congress.

Obamacare, the signature domestic policy achievement of the Obama administration already survived an existential challenge at the U.S. Supreme Court in 2012, and nearly 12 million Americans signed up for coverage under the law for 2018.