Do Christie and Pence Make It 2016 Again? Not Yet.

It’s been feeling a bit like 2016 lately.

Back then, the opposition to Donald J. Trump was badly divided. The party couldn’t coalesce behind one candidate, allowing Mr. Trump to win the Republican primary with well under half of the vote.

With Mike Pence and Chris Christie bringing the field up to 10 candidates this week, it’s easy to wonder whether the same conditions might be falling into place again. Despite high hopes at the start of the year, Ron DeSantis has failed to consolidate Trump-skeptic voters and donors alike. Now, the likes of Mr. Pence and Mr. Christie — as well as Tim Scott and Nikki Haley — are in the fray and threatening to leave the Trump opposition hopelessly divided, as it was seven years ago.

In the end, Mr. Pence or Mr. Christie might well break out and leave the opposition to Mr. Trump as fractured as it was in 2016. But it’s worth noting that, so far, the opposition to Mr. Trump has been far more unified than it ever was back then. It’s not 2016, at least not yet.

So far this cycle, polls have consistently shown Mr. DeSantis with the support of a majority of Republican voters who don’t support Mr. Trump. Nothing like this happened in that past primary, when at various points five different candidates could claim to be the strongest “not-Trump” candidate, and none came even close to consolidating so much of the opposition to Mr. Trump. Ted Cruz got there eventually, but only after a majority of delegates had been awarded and it was down to him and John Kasich.

Perhaps surprisingly, Mr. DeSantis’s share of not-Trump voters has remained constant, even though his own support has dropped. This suggests Mr. DeSantis has mainly bled support to Mr. Trump, not to another not-Trump rival. It also suggests that the other not-Trump candidates may have bled support to Mr. Trump over the last half year as well.

Of course, all of this could change if another candidate gains in the polls. Perhaps Mr. Christie or Mr. Pence — or even Mr. Scott or Ms. Haley — will ultimately break out and take support away from Mr. DeSantis. On paper, it’s not hard to see how Mr. DeSantis might be vulnerable to candidates like these. Mr. Pence might run as a forcefully anti-abortion candidate, threatening to peel away socially conservative evangelical Iowa caucusgoers on Mr. DeSantis’s right. To his left, Mr. Christie could run as a forcefully anti-Trump candidate, channeling the passions of many of the relatively moderate voters who might be most likely to oppose the former president.

Those threats to Mr. DeSantis may be real, but Mr. Christie and Mr. Pence may not be the right candidates to capitalize on his vulnerabilities. They enter the race with staggeringly poor favorability ratings. In the most recent Monmouth poll, Mr. Pence’s favorability rating was at 46 percent among Republican leaners, compared with 35 percent who had an unfavorable view. Mr. Christie’s ratings were even worse: Just 21 percent had a favorable view, compared with 47 percent unfavorable. That’s even lower than the 22 percent favorability rating of Vivek Ramaswamy, one of the lesser-known Republican candidates.

Mr. DeSantis seems to have a narrow path to victory. Even limited support for Mr. Pence or Mr. Christie could be enough to close it off — including in the must-win Iowa caucus. But so far, there’s only one plausibly viable candidate against Mr. Trump. For now, Mr. DeSantis is strong enough to deny a serious opportunity to another not-Trump candidate, even if he hasn’t been so strong that these candidates wouldn’t take a chance.

His bigger problem is Mr. Trump, who after eight years as the leader of the Republican Party is a far more formidable primary candidate than he was in 2015-16. He’s strong enough that Mr. DeSantis trails him even in a one-on-one race, without any other candidate entered in the fray.