Nikki Haley became the second officially-announced presidential candidate from either of the two major American political parties yesterday. Initially she had teased that her big announcement would be today, but she must have been overcome with the Valentine's Day spirit or something, so she jumped the gun. Haley and Donald Trump are now the entire "officially-announced" field for 2024. Which immediately leads me to wonder: "Who's next?"

On the Democratic side of things, President Joe Biden may have already frozen the entire field, even before he makes his re-election bid official. The Democratic successes in the 2022 midterms bolstered Biden, and his average job approval ratings are now higher than they have been since late 2021 (at just over 44 percent). So there likely won't be any surprises from the Democrats this time around. The public is not exactly overjoyed with the concept of Biden running for a second term, but then again neither is it a particularly frightening concept to them either. Biden is seen -- as he was in 2020 -- as rather boring but also competent and effective. The biggest negative about Biden running is seen as his advanced age, not his policies or his personality.

But the Republican field is likely to be just as lively as it was in 2016. Back then, the Republican field was enormous, with well over a dozen candidates vying for the primaries. This time around, Donald Trump is seen as vulnerable -- something that wasn't true in 2020, when Trump (just as Biden seems to have done this time around) froze out the Republican field by being an incumbent president. This time, Trump will run with a lot more competition -- and a lot more baggage. The worst negative about Trump (to Republican primary voters) is that he is now seen as a loser. The party has had three disappointing election cycles in a row (2018, 2020, and 2022), and many GOP voters directly blame Trump for this dismal record -- most especially the 2022 midterms, where many of Trump's hand-picked MAGA candidates went down in flames. If it hadn't been for Trump, the Republicans might have a three- or four-seat majority in the Senate right now, to put this another way.

Haley, sensing Trump's weakness, jumped in the race to be the first official non-Trump GOP candidate. But she's got a long way to go with the base voters -- her measured support among Republican voters is currently somewhere between "non-existent" and "incredibly tiny." There is, however, one GOP candidate who is already challenging Trump's hold on the primary voters: Florida Governor Ron DeSantis. He is the early lead in the contest to be the last candidate standing other than Trump. But leads that happen this early can often peak way too early too, so it's impossible to know if DeSantis has any sort of staying power on the national stage or not. If being a successful GOP governor of the Sunshine State were any kind of guarantee of victory in the primaries, Jeb Bush would have been the 2016 nominee, after all.

Bush, of course, was absolutely savaged by Trump. So far, Trump has only been halfhearted (at best) in his attacks against both DeSantis and Haley. He hasn't unleashed broadside after broadside at either one of them, which for him counts as restrained. Other Republicans who are considering a run must be watching this dynamic closely, to see how it develops. Getting on Trump's bad side isn't the Republican political suicide that it once was, but it would still be a stiff headwind to have to fight in a primary race.

Which is why waiting for and speculating about the next campaign announcement is most likely going to be a fun game for the whole family to play for the next two or three months -- perhaps even all the way through summer. DeSantis seems in no rush to make an official announcement, but then he's got the luxury of waiting, due to how often he has been hyped in the national media as the best "not-Trump" candidate around. DeSantis also has a legislative session to get through in Florida, so he may wait until a lot more candidates are in the race before he announces. As I said, he's got the luxury of doing so mostly because his name recognition is so high among Republican voters already.

For the rest of the GOP wannabes, however, getting in earlier is going to look more and more tempting now that Nikki Haley has broken the ice, especially if Trump continues to hold his major fire over Haley's candidacy. Getting in earlier means being able to line up big donors early (before they've all committed to someone else) and building a ground operation in the early-voting states. And, as mentioned, beginning to build name recognition with the public -- which is crucial. Waiting for others to jump in first is going to make less and less sense as time goes by, that's my guess at any rate. And once the third and fourth candidates toss their hats in the ring, the dam may burst and we may get a whole flood of them all at once (if you'll pardon the mixed metaphor). There will be a "safety in numbers" theme to this, since Trump won't be attacking every other candidate with equal fervor. And other than DeSantis (or perhaps Mike Pence), nobody's going to want to be the last one to jump in the race.

If this cycle turns out anything like the 2016 cycle, we'll once again wind up with at least a dozen major contenders on the Republican side. There are certainly more of them than that who are already actively considering a bid. This brings up another aspect that all the possible candidates (as well as the entire Republican establishment) are already worried about -- the larger the field gets, the more this might help Trump win. This is likely the explanation why Trump (so far) has mostly restrained himself from launching vicious attacks.

Trump, back in 2016, won most of his primaries (all except the ones at the very end of the process) with only around one-third the vote in each state. To put it another way, two-thirds of Republican voters voted against Trump. But he won anyway. Because that two-thirds was sliced and diced between so many other candidates. The Republican Party designed its primary rules to have a winner emerge as early as possible. They award the lion's share of each state's delegates to the winner -- no matter what percentage of the vote he or she actually gets. Second or third place don't count for much in GOP primaries. Democrats have adopted a more proportional system, which gives challengers more of a chance by dividing each state's delegates more evenly, but this also tends to extend the process later in the calendar. On the Republican side, Trump used this to his advantage. And he could very well do exactly the same thing again.

People around Trump must have explained this to him. He lived through it in 2016, so he should know what it all means. The more contenders for the "not-Trump" candidate there are, the better his chances are going to be. Which is why he's likely not launching endless broadsides against Haley or even DeSantis quite yet. "The more the merrier" is likely dictating Trump's response, at this point.

Other Republicans are also fully aware of this whole dynamic -- especially the donor class. There is a real push to get any Republican candidate to swear that if they don't catch fire in the polls very early on, then they will gracefully drop out -- early. Even before the first primary is held, perhaps. This may be the only way the rest of the candidates will have any chance of actually beating Trump for the nomination. It is little-remembered now, but Joe Biden's 2020 path to victory on Super Tuesday was prepared by two major Democratic candidates (Pete Buttigieg and Amy Klobuchar) officially giving up right before it happened and fully endorsing Biden. This was to counter the insurgency of the Bernie Sanders campaign, for those who have forgotten. Republicans are going to want the same sort of thing to happen in the GOP primaries this time around -- even if a whole bunch of them run, they all need to realize very early if they're not going to wind up in a one-on-one contest with Trump, and then gracefully bow out to clear that lane for a stronger candidate.

Donald Trump announced incredibly early in the campaign cycle, for a number of reasons (not least of which was his effort to shield himself from judicial proceedings). His original plan was to score a huge "red wave" victory in the midterms and then immediately consolidate the entire party behind him and freeze all the other wannabes out of the field. This did not work out as planned, obviously. The field is not frozen, although at least a few perhaps-viable challengers have decided to wait at least another four years before running -- so it did work to some extent, at least. But this leaves plenty of others who appear to already be unofficially campaigning (doing book tours, visiting Iowa and all the other early-voting states, convincing big donors behind the scenes, etc.), most of whom will eventually make their own formal campaign announcements.

Nikki Haley has now officially opened this door. Who will be the next to walk through it? It's anybody's guess, really. I'm going to take a longshot stab at guessing, and predict Larry Hogan (ex-governor of Maryland) will be the third Republican candidate to announce. But because there are so many of them to choose between, I realize I will probably wind up being wrong about that. As I said, it's really anybody's guess who's going to be next.

-- Chris Weigant

Follow Chris on Twitter: @ChrisWeigant