(CNN) The decision by a federal judge in Texas to side with Republicans to strike down Obamacare has opened up a new front in the long political fight over the transformative health care law.

While Democrats across ideological lines are in lockstep opposition to GOP efforts to unwind Obamacare, the Friday ruling also highlighted deep-seated policy rifts over what comes next. The internal debate over health care lies at the center of a broader argument between the Democratic establishment and its progressive grassroots -- a conflict that figures to roil the party's 2020 presidential primaries.

Among some of the country's most ambitious liberal leaders, there is a broad divide over whether to simply secure and save Obamacare, ramp up to a fully government-backed plan, or aim for something in between.

When the Texas ruling came down, President Donald Trump crowed , "As I predicted all along, Obamacare has been struck down as an UNCONSTITUTIONAL disaster! Now Congress must pass a STRONG law that provides GREAT healthcare and protects pre-existing conditions. Mitch and Nancy, get it done!"

Unstated by Trump: Obamacare already offers the protections Trump is asking Congress to deliver. In terms of specifics, this is about where the White House was in early 2017, before the Republican majorities on Capitol Hill failed to explicitly repeal and replace the law.

So with the GOP now mostly limiting itself to firing spitballs from the sideline, newly empowered House Democrats and their Senate allies have been presented with a massive opportunity to push forward and map out the future of health care in America -- if they can ever agree on their strategy first.

The 'Medicare for all' lifers

The ruling should give a boost to the progressive grass roots, which has argued for some time that intransigent Republicans should be met with ambitious, uncompromising Democratic alternatives.

After all, they argue, Obamacare was crafted from a conservative health care blueprint (once derided as "Romneycare") that further embedded private, for-profit insurers into the system. And look how that turned out.

"Medicare for all," one form of single-payer health care, would be run by the government and funded with taxpayer dollars. Supporters argue that the public expense would be more than offset by the elimination of premiums, co-pays and deductibles. The highest-profile iteration of the plan, as articulated in a bill from Vermont independent Sen. Bernie Sanders last year, would over a four-year period eliminate private plans and create a system in line with the Canadian model.

Sanders' 2017 bill was co-sponsored by 16 Senate Democrats, including fellow potential 2020 contenders Sens. Elizabeth Warren, Kamala Harris, Cory Booker, Jeff Merkley and Kirsten Gillibrand, who had a big hand in mapping out the transition process.

Going into the new year, Sanders and single-payer backers will have new and increasingly powerful friends among House Democrats, who have been tabling a companion bill for years. High-profile freshmen Reps.-elect Alexandria Ocasio-Cortez, Ayanna Pressley and Rashida Tlaib (among others) are expected to join incumbent progressive leaders like Reps. Pramila Jayapal, Mark Pocan and Ro Khanna in the new and growing "Medicare for all" caucus.

The 'buy-in' club

The fight to save Obamacare in 2017 united Democrats and pulled in further left groups like the Democratic Socialists of America, but that détente, which mostly extended into the 2018 midterms, is quickly fading. Still, the party's progressive trajectory has helped spawn a number of plans for expanding care, both from lawmakers and think tanks.

One of them, which would allow people 50 and older to buy into Medicare, will be a priority for the new Democratic House majority -- a pledge New York Rep. Brian Higgins secured from Minority Leader Nancy Pelosi in exchange for his support in her bid to reclaim the speakership.

Some of these proposals have been pitched as stepping stones toward single-payer. Others are plainly supportive of maintaining the broad strokes of the current system, with employer-sponsored private plans keeping a central role. They would mostly all create some form of a "public option," which would allow people who are not insured through work (or currently eligible for Medicare or Medicaid) to purchase a government-run plan.

Merkley and Sen. Chris Murphy's "Choose Medicare" bill is probably the most aggressive. It allows some workers to buy-in with their company's approval and, once they sign on, have the option to stay on regardless of a subsequent employer's policy.

In October 2017, Sen. Brian Schatz and Rep. Ben Ray Luján introduced Medicaid buy-in legislation called the "State Public Option Act," which would permit the states to offer coverage under Medicaid.

For all their differences, these plans (there are a handful more) would all -- in the estimation of their authors -- drive down prices by injecting the government, which doesn't have shareholders or executives to pay, into the marketplace.

Again, there is a lot of overlap here with "Medicare for all" supporters. Merkley, for instance, is a vocal proponent of the Sanders bill but also has legislation in this bucket. Others are more difficult to read.

Someone like Rep. Beto O'Rourke, the popular Texan with an eye on a presidential run, could probably claim a spot in all three groups. On the trail during his near-miss challenge to Republican Sen. Ted Cruz this year, he touted "universal, guaranteed, high-quality health care for all" -- which, though actually a neat encapsulation of the Democratic mood at the moment, makes him difficult to place.

"We need a single-payer healthcare system for all Americans," O'Rourke wrote on Facebook in October 2017. But he was not among the cosponsors of the House "Medicare for all" bill that same year.

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The 'save Obamacare and build on it slowly' crowd

It's hard to find anyone with any sway or ambitions in Democratic politics in 2018 who doesn't, at the very least, want to preserve, patch up and eventually grow large parts of Obamacare.

Even in red states, Democrats during the midterms talked up the law's safeguard for people with pre-existing conditions, which became a major talking point in part because it has come under threat by the GOP lawsuit, the benefits of Medicaid expansion under the law and a need to reduce prescription drug prices.

Shortly after last month's elections, Massachusetts Rep. Richard Neal stated the position simply: "Let's defend Medicare and Social Security, and you know what? Let's fix pre-existing conditions so there's never a threat to it again."

As long as Republicans control the Senate and Trump is in office, that's about as much as Democrats can hope for.

Looking ahead to 2020, former Vice President Joe Biden would likely begin a potential campaign in this camp. Biden has frequently discussed health care as a right but is yet to stake out a claim in this newer debate.