Jeb Bush and Mitt Romney both have expressed that they are considering running for president in 2016. (Melina Mara/The Washington Post)

In case you haven’t been paying attention to the 2016 Republican presidential race — and you should be, given that the election is a mere 652 days away — there was an interesting development last week: Everyone is running. Really, everyone.

Consider:

●Sen. Marco Rubio of Florida convened a strategy session in the Sunshine State with his finance team over the weekend. And he is bringing on Anna Rogers, finance director for the conservative super PAC American Crossroads, to head up fundraising for his PAC.

●Sarah Palin said while “serving wild-boar chili to the homeless” at the Salvation Army in Las Vegas late last week that she was “interested” in the race. Over the weekend in Iowa, Palin said she was “seriously interested.” I am skeptical.

●Wisconsin Gov. Scott Walker just signed on David Polyansky, who served as senior strategist for Sen. Joni Ernst’s 2014 campaign, to be his lead man in the key state of Iowa.

2012 nominee Mitt Romney and former Florida governor Jeb Bush powwowed in Salt Lake City on Thursday to discuss “the future,” Bush said.

●Sen. Lindsey O. Graham of South Carolina is setting up a “testing the waters” committee.

●Seven potential candidates, including New Jersey Gov. Chris Christie, attended a forum hosted by conservative Rep. Steve King of Iowa.

●Ohio Gov. John Kasich told conservative radio host Hugh Hewitt that he is considering the contest.

According to Politics1.com, which keeps track of these sorts of things, there are 25 (!) potential candidates for the Republican presidential nomination.

Given those two dozen aspirants, it’s a near-certainty that the 2016 field will be the biggest in the modern history of Republican nominating fights. (In both 2008 and 2012, 12 candidates ran.)

The reason is simple: The field — even with Bush and maybe even Romney in it — is more wide open than any race for the GOP nomination in more than two decades. There’s no heavy favorite; heck, there’s barely a front-runner.

In Washington Post-ABC News polling conducted in December, Romney led the field with 20 percent, followed by Bush at 10 percent, and 12 candidates were bunched between 9 percent and 2 percent. Compared with the past four competitive Republican presidential primaries — going back to 1988 — that’s the most muddled field to date.

The rush of candidates will also have consequences — particularly if even two-thirds of those who are talking about running actually, well, run.

The biggest impact will be on fundraising. A race featuring Bush, Romney, Christie, Walker and Rubio would put enormous pressure on the party’s major-donor class to choose sides among candidates they know and like. And although the party establishment and its major donors have lots and lots of money — it’s by far the biggest money pot on the GOP side — it’s hard to see all five of those candidates being able to raise the $75 million or more each probably needs to run a serious campaign in Iowa, New Hampshire, South Carolina and beyond.

The second major effect of such a large field of serious candidates is that the Republican National Committee’s hopes of quickly choosing a nominee and focusing the party’s time (and money) on the likely Democratic nominee, Hillary Rodham Clinton, might be dashed. It takes a while to winnow down a field that has, say, 16 to 20 candidates in it. That’s especially true if a bunch of states move their primaries forward in hopes of getting attention (and an economic boost).

The more states that vote early-ish in the calendar, the more likely it is that candidates will target a state or two where they have the best chance of winning rather than trying to run the table. And assuming that several candidates win some of those early states, it will be hard for the party to squeeze out someone who can say: “Hey, I’ve won a state. I have delegates.” That could mean a nominating process that drags on well into the spring — and might, under certain scenarios, create at least the specter of a brokered GOP convention.

Now, looking at the race isn’t the same thing as running in the race. There’s an I-won’t-blink-until-you-blink aspect to all of this posturing. But the past week suggests that the GOP field, which is big, is going to get even bigger. Maybe a lot bigger.