DES MOINES, Iowa -- Three Democratic presidential primary candidates who didn’t qualify for Tuesday’s nomination debate will still get their messages out even though they won’t be on stage at the primetime showdown.

Former New York City Mayor Mike Bloomberg is running a commercial on national cable TV on CNN, the network that's televising the debate, as well as on MSNBC.

“By the way, I’m the only candidate in the race who doesn’t take a penny in contributions from anyone. No big donors. No special interests. Nothing. The party rules prevent me from debating. If they change the rules, I’ll be happy to join it,” Bloomberg says in the 30-second spot.

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The multibillionaire business and media mogul reached the Democratic National Committee’s (DNC) polling criteria to qualify for the debate, but since he isn’t fundraising, he wasn’t able to hit the individual donor threshold required to make the stage.

In the commercial, Bloomberg goes on to say that “in the meantime, I’m traveling the country, speaking and taking your questions and making the case that Donald Trump has to go.”

Former Rep. John Delaney of Maryland, a long shot for the nomination, is running a 60-second TV commercial in Iowa, which kicks off the presidential primary and caucus nominating calendar in just 20 days.

“Hello Iowa. I want to tell you why I stayed in this fight for you, after visiting all 99 counties and doing more events than any candidate,” Delaney says in the ad.

The candidate touts his “unique ideas on health care, innovation, infrastructure, trade, climate, and national security and national service” in the spot and highlights why he’s the only White House hopeful “running with a real plan to bring jobs and entrepreneurship to small towns that are shrinking and aging and being left behind."

Delaney failed to reach either the donor or polling thresholds. Former Massachusetts Gov. Deval Patrick also didn’t come close to qualifying for the debate.

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Patrick -- who declared his candidacy for president just two months ago -- is running a TV commercial on CNN's New Hampshire airwaves during debate night. Patrick is spending much of his time campaigning in the state that holds the first primary in the race for the White House.

Highlighting his resume, Patrick explains in the ad that “I’ve led the civil rights division in the U.S. Department of Justice, worked to make businesses more fair and socially responsible, and delivered first-in-the-nation results as the only Democrat elected governor of Massachusetts in 30 years. I’m living my American dream and I’m running for president to be sure you get to live yours.”

With Sen. Cory Booker of New Jersey ending his White House bid on Monday, Patrick is the only remaining African-American candidate left in a Democratic field that has shrunk to 12 candidates.

The other non-white candidates in the field -- Rep. Tulsi Gabbard of Hawaii and entrepreneur Andrew Yang -- also didn’t qualify for the showdown. That will result, for the first time this election cycle, in an all Caucasian Democratic debate.

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Early Tuesday, Patrick took aim at Democratic Party leaders over the lack of diversity.

“Tonight, six candidates will take the debate stage, all remarkable public servants. Yet tonight America will not see herself in full,” Patrick said in a statement.

“The racial and ethnic diversity of the Democratic field, and our willingness to speak directly to issues of racism, has made me proud to be a Democrat and an American. But the debates have stopped either showcasing the field or representing the nation,” he added.

And taking aim at the DNC’s criteria, he argued that “instead of helping Democrats to choose our most compelling nominee from a range of diverse talent, the debates have become an end in themselves, an episode of reality TV with candidates paying more attention to polling numbers and donations than issues and people.”

Fox News' Alexandra Rego and Kelly Phares contributed to this report.