The most unpopular part of Obamacare now has a champion in the Republican presidential field. Via the Right Scoop, Donald Trump was asked on Thursday night by CNN's Anderson Cooper, "If…there's no mandate for everybody to have insurance, what's to—why would an insurance company not have a preexisting—insure somebody with a preexisting condition?" Trump replied, "Well, I like the mandate. Okay, so here's where I'm a little bit different. I don't want people dying on the streets. And I say this all the time."

Well, that's certainly "a little bit different"—in fact, it's hard to get a lot more "different" than to run for president as a Republican and support the hated cornerstone of President Obama's signature legislation. This "mandate for everybody to have insurance" is, of course, the unprecedented requirement that, for the first time in the more than 200 years of United States history, private American citizens must buy a product or service of the federal government's choosing merely as a condition of living in their own country.

To the best of my knowledge, not since Mitt Romney has a prominent Republican officeholder or top-tier candidate for office expressed fondness for the individual mandate.

But Trump went further even than that. He implied that those who oppose Obamacare's liberty-sapping mandate do "want people dying in the streets."

With the exception of Jeb Bush, no current Republican presidential candidate has yet advanced an Obamacare alternative. As a result, the GOP candidates have failed to elevate the most important domestic issue of the Obama presidency or demonstrate that they know how to lead the way to full repeal. But at least they don't support Obamacare's coercive core.

Indeed, Obamacare's individual mandate is not only coercive but unconstitutional. Obama's congressional allies claimed that passing it was a valid exercise of their authority to regulate interstate commerce, but the mandate was rejected as unconstitutional on those grounds by the Supreme Court—with Justice Scalia in the majority on this question—because in truth it was an effort to compel commerce, not regulate it. The mandate was rescued only because five of the Court's nine justices decided that it could plausibly be reinterpreted as a constitutionally permissible "tax"—even though Obama had insisted all along that it wasn't a tax, and even though the legislative text declares it to be an "individual responsibility requirement" paired with a "penalty" for noncompliance.

Imagine, if you would, a health care debate between Hillary Clinton and Donald Trump.

Jeffrey H. Anderson, author of "An Alternative to Obamacare," is a Hudson institute senior fellow.