Most of the discussion of the Trump administration's decision not to defend the Affordable Care Act — and to urge the courts to throw out its protections for people with pre-existing medical conditions — has focused on what happens to the individual insurance market. But the political impact may be even greater.

Why it matters: Protections for people with pre-existing conditions are hugely popular, and the administration may have handed Democrats their strongest health care weapon yet — because now they can make the case that the administration has gone to court to take away protections for people with pre-existing medical conditions.

The case is also likely to drag on, so it could be the political gift that keeps on giving through 2020, even if it is eventually thrown out.

The back story: The lawsuit that the Trump administration has embraced is the latest assault on the ACA’s marketplaces, and appears to be motivated both by continuing anti-ACA sentiment and a belief that the ACA’s consumer protections drive up rates. No alternative to protect people with pre-existing conditions is offered.

The impact:

A lot of people would be affected. Our analysis at the Kaiser Family Foundation found that 52 million non-elderly adults had pre-existing conditions that would have made them uninsurable prior to passage of the ACA. Even more people had health conditions that would lead to premium surcharges based on their health.

And they know it. Our March tracking poll found majority support across the board for prohibiting insurers from charging sick people more: 84% of Democrats support that part of the ACA, but so do 68% of independents and 59% of Republicans.

64% of Republicans still favor repeal of the ACA, but they do not favor repeal of protections for people with pre-existing conditions.

What to watch: The denial of protections under the lawsuit would apply only to people in the individual market, because people in the group market are protected under other federal laws. But it may not play that way in the real world. Everyone with a pre-existing condition would likely be scared, just as most Americans were worried that their rates were increasing when rates spiked in the relatively small non-group market.

Polls show that the public largely holds the Trump administration and Republicans in Congress responsible for problems with the ACA, and Democrats are accusing Republicans of ACA "sabotage." Republicans claim the problems are with the ACA itself, and they'd still like to repeal it — or change the subject to their repeal of the unpopular individual mandate penalty.

This lawsuit ending protections for people with pre-existing conditions changes the equation. It's an action the administration and Republican states will have taken directly themselves that would end these popular protections.

The bottom line: Democrats will try to force Republican candidates to take a position on the lawsuit. The question is how far Democrats will hit this this slow curve ball.