Biden may have spiked NH’s first primary to avoid a challenger. Ironically, he just made it easier for someone like Bernie Sanders to run.

Polls last week tell the story. One from the University of New Hampshire found two-thirds of New Hampshire Democrats don’t want Biden to run for reelection, and if he does, he is statistically tied with some of his 2020 rivals, including his own transportation secretary, Pete Buttigieg. But a poll of South Carolina Democrats found far more support for another Biden run: only a third wanted him to step aside.

South Carolina has been unusually good to Biden. In 2020, after he finished fourth in the Iowa caucuses, fifth in the New Hampshire primary, and second in the Nevada caucuses, he scored his first solid win in South Carolina.

Within 72 hours, many of the remaining Democratic presidential candidates dropped out and endorsed him. And then Biden hit big on Super Tuesday and steamed ahead to the nomination.

So the theory goes, if Biden was worried about a primary challenge, he should try to kick off the process in South Carolina versus states where Democratic voters previously rejected him.

If this is the thinking, then Biden and his team have reason to be paranoid. In the late summer, there were a number of polls, including one from the New York Times, that found Democratic voters didn’t want him to run again.

The climate has changed since then: gas prices are down, the Afghanistan debacle is receding from memory, Democrats had a better-than-expected midterm election, and Donald Trump is officially running again for president.

But, ironically, the move to reshuffle New Hampshire’s primary status may have made it more likely that Biden could be — if not challenged in a primary — more easily hurt politically.

As we move into 2023, there’s more confusion than at any time in recent memory about the upcoming presidential election. Specifically, we have no idea who will run for president, nor where they will even campaign and compete.

But we do know this at least on the Democratic side: New Hampshire will likely break Democratic National Committee rules and hold the nation’s first primary. And we know that if any candidates dare to show up and campaign in states that break DNC rules, they’ll be punished like never before. Among the penalties: They’ll be denied any spot on a DNC-sponsored debate stage.

The effect of this, however, is that it allows protest candidates to have a platform to say whatever it is they want, get press for it, and perhaps influence Biden, the Democratic agenda, and even national politics.

If Biden does run, there will be little appetite among donors and activists for anyone to challenge him in a primary. Among Democrats, Biden is widely viewed as the person who denied Trump a second term and he needs to be widely praised for that.

They also know that if a president faces a primary challenge it can be very damaging. Consider this: since 1968, no president who faced a primary challenge was reelected. It was true for Lyndon Johnson then, as it was later for Gerald Ford, Jimmy Carter, George H.W. Bush, and, well, Trump.

But the recent move by the DNC lowers the vitriol that could be directed toward, say, a progressive who feels Biden is too moderate. Put another way, it lowers the political risk of running.

Let’s consider the case of Bernie Sanders.

Sanders is 81, and the Vermont senator likely knows he’ll never be elected president. He is also a true believer in his style of politics, and gets that his presidential campaigns have helped other progressives get organized and involved and run for things like state legislature and city councils.

Last month, it was notable that his former campaign manager also said on CBS News that Sanders hadn’t ruled out a run for president should Biden not run, a sign it’s not completely off the table.

With the new primary calendar rules, it’s possible for Sanders to “run” in the New Hampshire primary, since it’s technically not a direct primary challenge to Biden. After all, the DNC rules mean New Hampshire, even if first, is nothing but a beauty contest.

And given that Sanders won the last two New Hampshire primaries, he would likely do extremely well and not embarrass himself if he ran in that primary.

And this could be a big problem for Biden. In 1968, when Eugene McCarthy primaried LBJ in New Hampshire, he got less than 40 percent of the vote. But that was enough of a rebuke for LBJ to bow out of the contest two weeks later. McCarthy didn’t become the nominee, but he played his role, embarrassing the incumbent president. Pat Buchanan did a similar thing to George H.W. Bush, who later went on to lose to Bill Clinton.

There are meaty topics Sanders wants to discuss that Biden doesn’t. A Green New Deal and Medicare for All are just starters. In the past week, Sanders pushed to end US involvement in a civil war in Yemen that is largely a proxy contest between Saudi Arabia and Iran.

Running in New Hampshire would give him a platform to talk about all this while saying with a straight face he isn’t running for real. And yet, it could give many members of the Democratic base reason to sit out the general election.

If not Sanders, then there are plenty of ambitious no-name members of Congress or mayors or governors who might use a protest run in N.H. as a springboard to a more credible candidacy in 2028.

None of this may happen, of course, But it’s ironic that Biden and his team opened the door to it when it was something they’ve been trying to prevent.

James Pindell can be reached at james.pindell@globe.com. Follow him @jamespindell and on Instagram @jameswpindell.