It’s common in other countries for heads of government to leave office and later return.

Winston Churchill led the United Kingdom through World War II only to see his party lose an election afterward.

Thereafter, the party won an election and Churchill returned as prime minister.

Yet in the United States, something similar has happened only once: Grover Cleveland was elected to the White House in 1884, lost in 1888, and won in 1892.

Thus, Cleveland became the 22nd and 24th president.

Or, now that we refer to the Bushes as Bush 41 and Bush 43, Cleveland was Cleveland 22 and Cleveland 24.

Any doubt that it has crossed Donald Trump’s mind to be Trump 45 and Trump 47 was removed at the 2021 Conservative Political Action Conference, or CPAC, in February in Orlando.

Trump, speaking of the 2024 Republican presidential nominee, subtly said he wondered who that will be.

Some – including Sen. Mitt Romney, R-Utah, the 2012 GOP standard bearer who isn’t exactly Trump’s biggest fan — have even said the nomination is Trump’s for the asking.

Anyway, if Trump and his supporters continue to be serious about his running again, it’s not too soon for them to assess their chances seriously.

¯ One factor is the issues.

The important issues in 2024 may well include those that have previously worked in Trump’s favor.

Among them are the judiciary, trade, jobs, border security, the swamp, and America’s vital national interests.

The differences between Trump and 2020 Democrat-presidential candidate Joe Biden were clear during the campaign.

Statements by multiple commentators and Republican officials lately that Biden ran as a centrist Democrat are incorrect.

Rather, Biden promised many times to be “the most progressive president” — read: the most liberal president — in American history.

That’s a promise he’s keeping, such as by (1) shutting down the Keystone XL pipeline, thereby cutting thousands of good-paying jobs and driving up the price of oil and gasoline, (2) creating a $1.9 trillion economic-stimulus bill that is an expensive liberal wish list, (3) requiring that athletes with XY chromosomes be allowed to compete against athletes with XX chromosomes, thereby putting the latter at obvious disadvantages, (4) in effect opening the southern border to many non-citizens seeking to enter the country illegally, and (5) doing so even for those having Corona Virus Disease 2019, or COVID-19, while (6) advocating and implementing contrasting COVID-19 approaches for much of the rest of the United States.

¯ Another factor is 2020 presidential-election illegalities, particularly those that can repeat themselves.

Regardless of whether such illegalities changed the outcome of the 2020 presidential election, there’s no serious doubt that they affected the result in that they at least affected popular-vote totals, and not in Trump’s favor.

As this column has explained before, including last week, we must not permit 2020 illegalities to repeat themselves, no matter whom they’d benefit.

¯ Another factor is whether Trump stays on message.

Whether he does so going forward is entirely under his control.

The effect of his not having done so previously isn’t entirely under his control.

Just as there’s no serious doubt that 2020 illegalities affected the 2020 presidential election’s result in that they at least affected popular-vote totals, and not in Trump’s favor, there’s also no serious doubt that Trump’s previously not staying on message worked against him in 2020.

It may take some convincing to get those who were potential 2020 Trump voters, but who cast 2020 ballots against him at least in part because he didn’t stay on message, to come around in 2024.

Staying on message would be worth the effort.

Dr. Randy Elf’s July 2020 open letter to then-President Trump urging him to stay on message is at www.post-journal.com/opinion/local-commentaries/2020/07/stay-on-message-mr-president and www.observertoday.com/opinion/commentary/2020/07/dear-mr-president-stay-on-message.