It has been a big few days for failed 2020 Democratic primary campaigns.

Let’s keep that momentum going.

The next three 2020 Democratic candidates who would do their party and American voters a favor and fold their doomed-to-fail candidacies are New York City Mayor Bill de Blasio, Colorado Sen. Michael Bennet, and Rep. Tim Ryan of Ohio.

Three is an arbitrary number. The selection of de Blasio, Bennet, and Ryan is also a bit arbitrary. But it's Friday, this is my list, and we are going by my rules.

Since July, neither Bennet, Ryan, nor de Blasio has cracked 2% in any of the many surveys conducted by multiple polling firms. In fact, in 80 surveys published between July 1 and now, only Bennet managed to hit 2%, and that happened only twice, according to polling data maintained by FiveThirtyEight. More importantly, de Blasio, Bennet, and Ryan bring nothing to the table that is not already being promoted by a better-polling, more exciting candidate. To put it bluntly, they are boring and have nothing to offer.

Maybe it is unfair to say the three should bow out now when they poll better than at least Miramar, Florida, Mayor Wayne Messam, according to a RealClearPolitics polling average. And maybe it is unfair to say they should quit when they poll better than or about the same as former Pennsylvania Rep. Joe Sestak and former Maryland Rep. John Delaney. Then again, with even worse polling numbers than Ryan, Bennet, and de Blasio, at least Messam and Sestak are not actively siphoning support and attention from the more worthwhile campaigns.

Further, Delaney may be polling terribly, but at least he has something to say, as he showed during the second round of Democratic primary debates in July. De Blasio, on the other hand, is just a worse-polling, more unpopular, and more unlikable version of 2020's current champions of ultra-liberal policies, Sens. Bernie Sanders and Elizabeth Warren. Ryan, for his part, is basically a younger, more inexperienced version of the folksy, moderate 2020 front-runner Joe Biden.

Left-wing billionaire philanthropist Tom Steyer, New Age guru Marianne Williamson, and Montana Gov. Steve Bullock all have terrible polling numbers as well, but they still perform better than de Blasio, Ryan, and Bennet, according to the RealClearPolitics polling average. Also, as an ultra-liberal climate change scaremonger, Steyer at least has something unique to say. Same goes for Williamson, whose candidacy has been anything but boring.

De Blasio, Ryan, and Bennet cannot say the same. They can’t break 1% in the polls, and that is most likely because they do not offer a product that someone better-known and more likable is not already offering.

So, let’s follow the lead of Rep. Seth Moulton, who announced Friday that he is ending his candidacy.

“I think it’s evident that this is now a three-way race between Biden, Warren, and Sanders, and really it’s a debate about how far left the party should go,” Moulton said.

The Massachusetts congressman’s announcement came not long after Washington Gov. Jay Inslee revealed that he, too, is exiting the race. And that announcement came just a few days after former Colorado Gov. John Hickenlooper announced that he would put down his 2020 candidacy.

Five down (don’t forget Rep. Eric Swalwell and Richard Ojeda of West Virginia), and roughly 21 more Democratic primary candidates to go.