Donald Trump was demolished in the 10th Republican presidential debate, but I#8217m not sure it will make any difference.

The problem is, the man who demolished him, Marco Rubio 2.0, was a newcomer to the debate stagemdashand the fact that we#8217d only seen the risk-averse Rubio 1.0 in the previous nine debates limited the feisty new guy#8217s credibility. His revised stance was obviously a political calculation in a year when the voters seem to be sick of political calculations.

Trump, by contrast, has been Trump right from the jump. He is authentically boorish and nasty. I#8217m not sure that you can suddenly transform yourself from grasshopper to gladiator and not seem a bit phony somehow, even though the Florida senator brought it off low-key, funny and well.

It is possible that Rubio#8217s assault on Trump will have the same effect as Chris Christie#8217s assault on Rubio: It may ding Donald a bit, but it may also have been a kamikaze mission, doing Rubio no good at all or even, perhaps, hurting him.

In my wildest moderate fantasy, the beneficiary of the combined Rubio-Cruz attack would redound to the benefit of John Kasich#8211who, yet again, established himself as the one candidate on the stage with both feet planted on Planet Earth. But that hasn#8217t happened in previous debates.

Aside from the central trash-Trump narrative, I found the discussion of Obamacaremdashand health care in generalmdashto be weird and misleading, and typical of what passes for #8220substantive#8221 discourse in these circuses. Let me take you into the weeds a bit:

Donald Trump is right about #8220the [state] lines#8221 which limit the market for purchasing health insurance, but he doesn#8217t have a clue about anything else. Obamacaremdashand its conservative predecessor, the Heritage Foundation planmdashdepend on market principles. Individual state markets (the term of art is #8220health care exchanges,#8221 which are websitesmdashlike Amazon or Travelocitymdashwhere purchasers can compare health insurance plans) are inefficient, and too many of them offer minimal choices. There was an effort to create larger, regional markets in the final stages of the Obamacare debate. For some obscure reasonmdashit probably has to do with insurance company lobbyingmdashthe idea was killed by moderate Democrats. Part of the problem was that most Republicans were refusing to negotiate. They were simply against the bill; if they#8217d participated, we might have had a much more effective program.

Donald Trump is wrong about #8220the lines#8221 being the most important thing. The most important thing is who pays for the people who work, but don#8217t make enough money to pay for health insurance? (Medicaid pays for the people who don#8217t work.) In a CBS News interview, Trump said bluntly: #8220The government#8217s gonna pay for it.#8221 Well, that#8217s one way to do it. Another is to impose an #8220individual mandate#8221mdashthat is, to require healthy young people who don#8217t think they need health insurance to buy some. The implicit deal is that young people have a moral and civil responsibility to pay into the system when they#8217re healthy so that the system will take care of them when they#8217re older and less healthy. The original Heritage plan, which John Kasich (wisely) supported in 1994 had a mandate.