GOP health plan is a start

House Republicans delivered a long-promised Obamacare replacement Monday night. It’s a strong bid to replace an increasingly feeble law. President Donald Trump tweeted his support for the “wonderful new” bill. Some other Republicans are in open revolt.

Let’s slow down here. There are some huge blanks still to be filled in: Will people lose coverage because they won’t be able to afford it as premium subsidies shrink, as critics claim? Will the plan cost the federal government more or less than an increasingly shaky Obamacare would? Health economists are busy at their calculators, so answers to those and other key questions should be forthcoming soon.

Many Americans now have Obamacare coverage in name only — that is, their insurance is expensive and almost useless because of explosively high deductibles or because the networks of doctors and hospitals is too narrowly drawn. Insurers are fleeing the program. Obamacare is coming apart at the seams.

So what does the GOP proposal do to fix that?

It frees American businesses and individuals from the mandate to buy or provide coverage or pay penalties. In its place, more personal responsibility: Those who don’t buy insurance, or who let their coverage lapse, can be charged more to buy later — a flat 30 percent surcharge. That’s a smarter and fairer system than letting people sign up for no added charge after they’re sick.

Also jettisoned would be the metal plans (gold, silver, bronze). In their place, more flexibility for insurers to offer different cost-sharing packages (including, we hope, more affordable co-pays and deductibles) to consumers. That could help reduce costs for some Americans.

The GOP plan preserves some of Obamacare’s most popular features. It allows parents to keep their children on policies until age 26. It prohibits insurers from denying coverage based on pre-existing conditions. Good.

One of the biggest battles is shaping up over the millions of people who have gained coverage via Obamacare’s Medicaid expansion. Generous Obamacare federal assistance enticed many states to massively expand their rolls. The new GOP plan phases out that increased federal assistance in 2020. After that, states could continue to provide expanded coverage, but presumably would be on the hook for more of the cost. Some GOP leaders fear Republicans will be blamed if millions lose Medicaid coverage. But we think lawmakers should start reining in Medicaid costs.

This Republican plan — titled the American Health Care Act — isn’t a done deal. Far from it. It’s already taking flak not just from Democrats who oppose repeal, but also fusillades of fire from Republican conservatives who want a complete repeal of Obamacare.

Democrats, meanwhile, said the plan would force millions of Americans to pay more for less care. That strikes us as a premature judgment: This plan has so many moving parts that bold predictions are little more than conjecture.

Let’s see whether insurers say the Republican plan would let them craft policies that people want and can afford.

For years Republicans have told voters that, given the chance, they would replace Obamacare with a more affordable, less onerous system. Their opening bid moves in that direction. Let the tussle to improve and pass it begin.