Mr. Bloomberg said he would mobilize his operation behind any of the Democratic candidates, even Ms. Warren, the Massachusetts senator, or Mr. Sanders, the Vermont senator. Mr. Bloomberg said he did not plan on running negative ads against any Democratic candidate, even those he strongly disagreed with.

“I really don’t agree with them,” he said, of Mr. Sanders and Ms. Warren, “but I’d still support them, yes, because compared to Donald Trump that’s easy.”

While most of the candidates are spending the bulk of their time in the first four primary states, Mr. Bloomberg is orienting his operation toward the Super Tuesday primaries in states like Texas on March 3, when about 40 percent of all the delegates are at stake.

With recent polling showing four candidates — Mr. Sanders, Ms. Warren, former Vice President Joseph R. Biden Jr. and former Mayor Pete Buttigieg of South Bend, Ind. — all in a position to win both Iowa and New Hampshire, Mr. Bloomberg could play an influential role in the primary process, once the race moves past the early contests. His aides have indicated that Mr. Bloomberg is not inclined to keep pouring money into an extended contest with Mr. Biden and would instead reorient his campaign into an organization dedicated to battering Mr. Trump, should the former vice president emerge as the leader in the race.

His spending, entirely self-funded, has meant that though Mr. Bloomberg meets the polling requirement for the party debates, he does not meet the donor qualifications for participating.

As he campaigned across Texas, Mr. Bloomberg cast that decision as a campaign strength, illustrating his independence from financial interests.

Yet he also criticized the party’s process, echoing concerns leveled by other candidates who say the rules set by the Democratic National Committee are excluding qualified contenders. Mr. Bloomberg will not appear on the debate stage on Tuesday, when the candidates meet in Des Moines for their final face-off before the Iowa caucuses.