As Republican Party politics becomes even more extreme, it’s common to see assorted GOP personalities make the transition from fringe figures to powerful mainstream players. Rep. Jim Jordan, for example, was described by former House Speaker John Boehner as a political “terrorist,” but the Ohio Republican is now chairman of the House Judiciary Committee. Several members of the right-wing House Freedom Caucus have similarly moved from the GOP periphery to positions of power.

But it’s not just people: Far-right ideas, previously championed by radical figures, have followed a similar trajectory. Take Republican opposition to birthright citizenship, for example.

When some GOP officials started talking about this nearly 20 years ago, conservative media outlets conceded that most Republican lawmakers “avoided the issue,” reluctant to get into a debate over amending the Constitution. In 2010, when then-Rep. Steve King targeted birthright citizenship, his bill garnered only 27 co-sponsors.

As we were reminded yesterday, the intra-party discussion has changed quite a bit. The Miami Herald reported:

Gov. Ron DeSantis on Monday unveiled a sweeping plan to overhaul the nation’s immigration system and ramp up border enforcement, vowing to end birthright citizenship, “repel the invasion” at the U.S. southern border and use the “levers at our disposal” to ensure cooperation from Mexico.

I was curious to see how, exactly, the governor intends to “end” birthright citizenship, but his plan was rather vague on the details: DeSantis, according to his own policy blueprint, simply intends to “take action to end” the policy. What kind of action? He didn’t say.

This comes roughly a month after Donald Trump vowed to end birthright citizenship by way of an executive order — as if presidents have the authority to announce that certain parts of the Constitution no longer count because they say so.

In case anyone needs a refresher, at issue is a debate over the Constitution’s Fourteenth Amendment. “All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside,” it reads.

The policy is known as birthright citizenship because the language of the amendment has been interpreted to mean that those born in the United States are citizens of the United States.

As The Washington Post’s Greg Sargent explained several years ago, the Fourteenth Amendment and birthright citizenship used to “rank among the great and defining accomplishments of the Republican Party, back when it was the Party of Lincoln.”

Greg talked to historian Eric Foner, who explained, “This was one of the historic achievements of the Republican Party. There’s plenty of irony here.” From Greg’s piece:

“The Civil War and the emancipation of the slaves shaped the Republican Party and pushed it in the direction of nationalism, inclusiveness, and openness,” Foner says. “The idea was that citizenship should be extended to people regardless of accidental characteristics, such as race, national origin, or the status of their parents. This established a national standard for citizenship. The principle was one of opportunity and inclusiveness. That’s what the Republican Party stood for. The 14th amendment became one of the defining principles of the Republican Party.”

That was eight years ago, as some GOP presidential candidates started expressing opposition to the constitutional principle.

Now, the top contender for the Republicans’ 2024 nomination is calling for the end of birthright citizenship — and so is his next closest competitor.

As is too often the case, the line between the GOP fringe and the GOP mainstream has blurred to the point that it hardly exists at all.

This post revises our related earlier coverage.