Robert I. Field, professor of law and professor of health management and policy at Drexel University, wrote this for the "Field Clinic" blog at philly.com: philly.com/fieldclinic.

Guess who supports universal health coverage?

"Everybody's got to be covered," Donald Trump declared on CBS's 60 Minutes last weekend.

The Donald, always full of surprises, promised, "I am going to take care of everybody. I don't care if it costs me votes or not." Courageous words, indeed.

Trump, along with all of his opponents for the Republican presidential nomination, calls for repealing Obamacare. But unlike most of the others, he has gone so far as to put forth a plan to replace it.

At least, he says he has. What he said on 60 Minutes was long on promises, but it misses one key element - any semblance of coherence.

How will Trumpcare take care of the uninsured? Easy. Trump will bring his famous deal-making skills to bear on hospitals. "I would make a deal with existing hospitals to take care of people."

Does that mean we would receive all of our care from hospitals? What about physicians, pharmacies, and outpatient clinics? Trump seems to have a lot more deal-making to do.

Who will pay for the care? That's also easy - the government. Say what? Is Trump proposing a huge new government social program? It sure sounds that way, although he didn't put it in those terms.

Where will the government get the money? Easier still. "We're going to save so much money on the other side." The other side of what? He didn't say. Apparently, that's another picky detail.

So, will Trumpcare turn our health care over to the government? Absolutely not. Trump insists it will be a private plan.

Here's how he described it: "But for the most it's going to be a private plan and people are going to be able to go out and negotiate great plans with lots of different competition with lots of competitors with great companies and they can have their doctors, they can have plans, they can have everything."

I'm not sure where to begin trying to figure out what that is supposed to mean. But I am encouraged knowing that we "can have everything." When have we ever heard that from a politician before?

You've got to give the Donald credit for consistency. He has supported the idea of universal coverage for more than a decade. But it is clear he hasn't given much thought to how he would actually implement it.

Health-care coverage is extremely complex, whether it is provided by the government or by private companies. Any universal plan must address thousands of interrelated issues, not to mention countless political concerns. That is why it took more than 100 years for America to adopt a plan that goes even part of the way, and why that plan, which we know as Obamacare, is so complex and controversial.

Making promises is easy. Devising a plan that is coherent and workable is not.

Forbes magazine said that in explaining his health plan, Trump was "kind of a mess." That is being charitable.