It took them a little longer than other observers to catch on. But Democrats have decided they have too many presidential candidates running for the White House this time. Way too many.

Twenty-four at last count.

If you want, you can see 20 of them on-stage for two solid hours each Wednesday and Thursday evenings.

Unseen those nights are four other wannabe Democrat presidents — a 20 percent larger field — who didn’t qualify for these events, according to the Democratic National Committee’s low bar for admission.

President Trump and the Republican National Committee, of course, are delighted. The more Democrats fighting and the longer they fight, the shorter time it leaves for that party to unite next year behind the final pick.

So, the merrier it would be for the GOP, which has one realistic candidate to focus on and raise money for from Day One.

There is a converse view, of course, that a large, diverse field competing will produce the best candidate. You can judge the diversity of views yourself on NBC starting tomorrow.

Ask Republicans about large fields; they had 17 in 2016, which guaranteed none would obtain majority support in the primaries. So, it’s quite possible Democrats too will select an unlikely nominee to run against the unlikely 2016 GOP nominee.

For the moment, Democrats are focused on offering more freebies to primary voters, despite wide agreement that their real goal is ousting Trump.

The newest Hill-HarrisX survey found nearly three-quarters of Democrats and Democrat-leaners agree there are too many presidential candidates. Eighty-eight percent of voters over 50 concurred. Sixteen percent said the field was like Goldilocks’ porridge, just about right.

Twelve percent, quite possibly smoking something, said the party needs more candidates.

A Des Moines Register poll in early June found 79 percent of likely caucus-goers wanted some candidates to drop out. So far, the collective answer has been, “You first.”

This week’s debates are crucial for much of the field. Although each individual’s time on-camera will be short, it will give them valuable national exposure and a priceless opportunity to plug their website to millions of viewers.

The second quarter of fundraising ends this weekend. So, time is short to stay in the running as media judge political support now by millions of dollar$.

After being accused of putting its thumb on the scale to favor Hillary Clinton last time, the DNC set low levels of qualification this time. But the criteria tightens for the third and fourth sets of debates come September and October.

Then, every debate participant must have at least two percent support in at least four polls (twice the current level).

And they must certify their campaigns got donations from a minimum 130,000 individuals and a minimum 400 individual donors in at least 20 states. That’s twice the current number of total donors.

Of course, none of this prohibits candidates from continuing to campaign. It just cuts off their national TV exposure, which will choke off money.