(CNN) Beto O'Rourke has held 154 town halls in venues like coffee shops, diners and houses since launching his presidential bid in March. On Tuesday, he'll hold his first one staged for national television .

The former congressman from Texas will participate Tuesday night in a CNN town hall in Des Moines, Iowa. It comes as part of a shift in strategy that has featured O'Rourke -- who prefers retail politicking at small events -- suddenly appearing on national broadcast and cable news outlets much more often.

O'Rourke's campaign has urged supporters to attend one of about 75 watch parties being held during the town hall.

The televised town hall format has boosted other Democratic candidates. South Bend, Indiana, Mayor Pete Buttigieg saw his profile rise after sharply criticizing Vice President Mike Pence during one in March. Massachusetts Sen. Elizabeth Warren's "I have a plan" mantra grew after appearances that showcased her policy mastery.

But O'Rourke, stung by a Vanity Fair cover immediately before his launch, stayed away from nationally televised town halls and interviews during the first two months of his campaign.

He took questions from reporters who attended his campaign events and did interviews with local outlets in the early-voting states. O'Rourke's preference has been to try to mimic his approach to the Texas Senate race last year, during which he visited all of the state's 254 counties. He packed his days with town halls in the early states and spent most of his time there taking questions -- and collecting anecdotes -- from the crowds, while livestreaming it all on Facebook.

Through it all, O'Rourke has maintained some key strengths. He raised $6.1 million in the first 24 hours of his campaign -- about the same as Vice President Joe Biden and Vermont Sen. Bernie Sanders, the Democratic race's top-two polling contenders (though O'Rourke's fundraising pace slowed compared to Sanders' in the weeks that followed). His hires of well-regarded veteran operatives at his El Paso headquarters and in the early states have impressed Democratic campaign pros. And his email list remains a powerful fundraising and organizing tool.

But his standing in the polls has dropped, with Biden entering the race weeks ago as a stronger-than-expected front-runner, Sanders remaining a well-known contender, and Warren and Buttigieg rising.

It's stirred talk that O'Rourke should have instead made another run for the Senate in Texas, this time against Republican John Cornyn.

"He came to see me at my home," former Senate Democratic leader Harry Reid of Nevada told The New York Times of O'Rourke. "I just lament he's not running for the Senate." Reid made a similar comment to Montana Gov. Steve Bullock, one of the most recent Democrats to jump into the 2020 race.

In an effort to rejuvenate his presidential campaign -- which hasn't yet benefited from the kinds of viral moments that catapulted him into the limelight as a Senate candidate last year -- O'Rourke recently began participating in nationally televised interviews.

He told MSNBC's Rachel Maddow he needed to do a "better job" finding ways to reach people who couldn't attend his town halls in person to "make sure that they can hear what this campaign is about and how I answer the questions that are put to me."

The interviews have at times sounded for O'Rourke, a former bassist in a punk rock band, like a studio album -- with the high points of his stump speech coming neatly packaged -- from a candidate who thinks he sounds better live, where he is more free-wheeling and less rehearsed.

Still, O'Rourke has acknowledged problems with his March entry into the Democratic primary field.

On ABC's "The View," O'Rourke conceded that the Vanity Fair cover that accompanied his campaign launch -- in which O'Rourke said he was "born to be in it," a comment that was widely mocked on social media -- lent him a "perception of privilege."

"I was attempting to say that I felt my calling was in public service," he said. "No one is born to be President of the United States of America -- least of all me."

O'Rourke in recent weeks has also moved to counter perceptions that he is light on policy.

He rolled out a $5 trillion proposal to combat climate change, and signed the No Fossil Fuel Money Pledge -- seeking to put an end to a question college students had repeatedly asked him at events by vowing to reject contributions from oil and gas industry executives.

This weekend, O'Rourke also proposed a series of measures aimed at reducing gun violence in a Houston Chronicle op-ed . His proposals include universal background checks, banning the sale of assault rifles, enacting a national "red flag" law that allows police or family members to ask a judge to remove firearms from people who could present a danger, and funding Centers for Disease Control and Prevention research into gun violence "so we can not only continue to understand what's happening but begin to address it."

Still, O'Rourke's willingness to outwork other Democratic candidates -- personally drive more miles and hold more events in more places -- remains the central selling point of his candidacy. On Monday, ahead of the CNN town hall, he visited the flood-ravaged Davenport, Iowa, and streamed his visit on Facebook.