Republican presidential candidate Donald Trump speaks during a rally at Iowa Central Community College in Fort Dodge on Thursday. (Charlie Neibergall/AP)

The Iowa caucuses are 11 weeks away. That is a lifetime in a political campaign. Except that it’s really not.

The campaign is about to enter its holiday period — a time when people, including Iowans and New Hampshire types, start paying much more attention to how to stuff their turkey and what’s under the Christmas tree than they do to politics. TV ads, stump speeches and even debates tend to get lost — or plain ignored — in the holiday maelstrom.

Thanksgiving is in less than two weeks. Christmas is four weeks after that. A week later, it’s New Year’s Eve/New Year’s Day. Suddenly, it’s Jan. 4, and the caucuses are only 28 days away.

That’s the real calendar math of 2016. The race is almost certain to freeze in place — or close to it — in 10 days, only to thaw a few days into the new year.

That prospect should worry Republicans who have an eye on retaking the White House after eight years in the political wilderness. Why? Because the top tier of the GOP field, as of today, is just two candidates large: former pediatric neurosurgeon Ben Carson and real estate investor Donald Trump.

In virtually every national poll of Republican voters, Carson and Trump not only lead the rest of the field by a wide margin, but also combine to take well north of 50 percent of the total vote. Carson is the favorite in Iowa, while Trump remains the front-runner in the New Hampshire primary.

The problem for Republicans is that in an election likely to be focused on foreign policy — the Paris attacks late last week make this an even greater likelihood — neither Carson nor Trump have demonstrated a depth of knowledge likely to reassure voters that they are up to the job of commander in chief.

Trump, in particular, would be a very problematic nominee for Republicans — not just because of his relative cluelessness on foreign policy but also because of his comments on immigration, women, prisoners of war, Iowans and lots (and lots) of other things.

Establishment Republicans had long believed that former Florida governor Jeb Bush’s massive financial edge — a super PAC that supports him raised $100 million in the first six months of the year — would allow him to overtake the likes of Carson and Trump as actual votes neared.

But Bush has been far less than advertised as a candidate, and it’s not clear that all the money in the world can sell a message that Republican caucus and primary voters simply don’t want to buy.

That leaves Marco Rubio, the senator from Florida, as the establishment pol best positioned to overtake the outsiders at the top of the field. And it could happen. But, Rubio’s fundraising has been less than impressive, and although he has moved up in polling, he has less than half of the support enjoyed by Trump or Carson in both early-state and national surveys.

Put simply: Any Republican who tells you that Trump and/or Carson are a fad who will fade before Iowa is engaging in the most wishful of thinking. It’s a near-certainty at this point that the top tier going into Iowa will look almost exactly like it does today — Carson and Trump at the top, with Rubio and Sen. Ted Cruz (Tex.) inching upward.

The state of the Democratic race is far less in flux — and, therefore, is causing much less agita for the party establishment.

Hillary Rodham Clinton, after months of listless campaigning, almost certainly secured the Democratic nomination with her strong showing in October — a month bookended by a standout performance in the first presidential debate and her marathon testimony in front of the House committee investigating the 2012 attacks in Benghazi, Libya.

Clinton remains far from a perfect candidate — her decision to exclusively use a private e-mail server while at the State Department will be a major point of emphasis for Republicans in the general election — but she is by far the most complete candidate in the Democratic field.

Vermont Sen. Bernie Sanders seems comfortable being a protest candidate rather than a serious challenger to Clinton — as evidenced by his refusal in each of the first two debates to use questions about Clinton’s e-mail issue to draw a broader contrast between the two candidates.

Sanders’s viability in Iowa and, especially, New Hampshire, a state where he is a slight favorite as of today, means that he will remain a relevant part of the race all the way through February. But it’s hard to see a path to victory for Sanders unless he can significantly expand his coalition beyond whites or peel voters off of Clinton — neither of which seem likely.

The state of both parties’ races today will almost certainly be the state of those races when actual voters begin to start paying attention again right around Jan. 4. That prospect should make Republicans frown and Democrats smile.