Donald Trump would appear to have done something very controversial (again) on Twitter Tuesday morning, registering his support for making flag-burning a crime punishable by as much as a year in jail or even the revoking of one's citizenship.

As our Philip Bump notes, it's not the first time Trump has pitted himself against things that have been defined by the Supreme Court as First Amendment rights — nor will it likely be the last. And as Bump also notes, Trump's decision to stand against flag-burning is likely to pit defenders of the practice “against the patriotism of people who find flag-burning unacceptable.”

But the size of that latter group might be bigger than the coverage of this topic suggests. And Trump's position probably won't strike most Americans as being all that controversial.

In fact, making flag-burning illegal appears to have had overwhelming public support as recently as a decade ago. It's controversial to attach such harsh penalties to it, and the fact it would require a constitutional amendment makes it a steeper climb, yes. But Trump's basic position is one that appears to have base-level appeal to a huge cross-section of Americans — no matter what the Supreme Court ruled about flag-burning in 1989.

Polling on this issue is not at all recent and varies widely. But if we walk through it poll by poll, you get a sense for how broad the underlying support is for what Trump is advocating.

First, the most recent quality poll, from the 2011 State of the First Amendment survey, showed 56 percent opposed a constitutional amendment (which would be required) to outlaw flag-burning.

Five years prior, though, in 2006, Gallup and CNN polling both showed 56 percent favored such a constitutional amendment.

And finally, if you look at a Fox News poll also conducted in 2006, it showed 73 percent thought flag-burning should be illegal.

These are all very different results, with little reason to believe there was some massive shift in public opinion in the intervening months and years. So what's up?

Well, it appears that people broadly do think — or at least did think a decade ago — that flag-burning should be illegal. But if you layer on top of that the fact that it would require a constitutional amendment to make it so, support falls. And if you layer on top of that the idea that this is a free-speech issue — as the first pollster did — it falls so drastically that people suddenly agree with the Supreme Court's ruling and oppose an amendment.

Here's the straight-up Fox News poll question that drew 73 percent support for making flag-burning illegal: “Do you think burning the American flag should be legal or illegal?”

And here's the State of the First Amendment question, which reduced support for outlawing flag-burning by 35 points: “Some people feel that the U.S. Constitution should be amended to make it illegal to burn or desecrate the American flag as a form of political dissent. Others say that the U.S. Constitution should not be amended to specifically prohibit flag burning or desecration. Do you think the U.S. Constitution should or should not be amended to prohibit burning or desecrating the American flag?”

And that poll isn't the only one to suggest a fuller description of free-speech concerns depresses support for an amendment. The same Gallup poll from 2006 happened to use the same wording as the State of the First Amendment poll in a separate question, and support for the amendment dropped from 56 percent to 45 percent.

Trump unpacked all kinds of constitutional issues when he brought up the idea of making flag-burning illegal. And, revoking the citizenship of offenders triggers a whole other constitutional debate — all of which is completely valid to debate.

But his basic position on whether flag-burning should be illegal is really no more controversial than believing Roe v. Wade or Citizens United should be overturned — or that any other Supreme Court decision was wrongly decided and should be reversed or amended.

Scott Clement contributed to this post.