Las Vegas, Nevada (CNN) On the eve of their next presidential primary debate, three Democratic contenders grappled with former New York City Mayor Michael Bloomberg 's presence on the stage for the first time.

Vermont Sen. Bernie Sanders previewed an attack on Bloomberg for supporting policies such as stop-and-frisk policing. Minnesota Sen. Amy Klobuchar criticized him for skipping the trudge of town halls and policy rollouts that the presidential campaign trail demands of most contenders. And former South Bend, Indiana, Mayor Pete Buttigieg said Bloomberg is attempting to buy the election.

The three candidates also focused on President Donald Trump on Tuesday night, with Buttigieg lambasting Trump for paying "hush money to a porn star."

Here are five takeaways from their town halls:

What to do with Bloomberg's money?

Bloomberg's hundreds of millions of dollars in television advertising has vaulted him into Wednesday night's Democratic debate . It's also raised questions about how other Democrats would handle Bloomberg's willingness to spend heavily to defeat Trump if they're the nominee.

On Tuesday night, the three candidates with town halls criticized Bloomberg for skipping the first four contests in Iowa, New Hampshire, Nevada and South Carolina, where he hasn't been or won't be on the ballot.

Buttigieg said he'd take Bloomberg's money. But he also said Bloomberg is attempting to buy the election.

"I mean, what else do you call it? What else do you call it when you dip into your endless reserves of millions and billions and don't go through the process of campaigning," he said.

Sanders called Bloomberg's strategy of skipping the first four states "obscene" and said the former New York mayor was trying to "buy the presidency."

But he didn't answer a question about whether he would accept hundreds of millions of dollars in help from Bloomberg if the Vermont senator becomes the Democratic nominee. Sanders touted raising seven million individual contributions, averaging $18.15 from a broad base of Americans.

"There is a point at which money ceases to be significant," he said. "We will have enough money to run a strong campaign. We will have enough money to defeat Donald Trump."

Klobuchar said she's glad Bloomberg will be on stage for the upcoming Democratic debate Wednesday night in Nevada.

"I actually thought he should be on the debate stage because I don't think you should just be able to buy your way to the presidency," she said.

Sanders: 'I do not believe in online bullying'

Sanders sought to fully divorce himself from supporters who have harassed others online and questioned whether anyone who believes in his agenda would attack a union leader.

Top officials at the Culinary Union in Nevada accused Sanders backers of swarming them online after fliers distributed by the union, which said Sanders would "end" their health care, went viral.

Sanders also questioned whether some of the social media comments cited by critics were, in fact, written by his supporters.

"The idea that anybody who works with me would make a vicious attack against a union leader just because we disagree on an issue is incomprehensible to me," Sanders said, "and you know what, I'm just not sure that that's true."

On the broader issue, Sanders was -- in his final point on the question -- unequivocal.

"I do not believe in online bullying," he said. "End of discussion."

'Having to send hush money to a porn star'

Buttigieg excoriated Trump and one of his most high-profile supporters for questioning his marriage to his husband, Chasten, on Tuesday, telling an audience in Las Vegas that his marriage "never involved me having to send hush money to a porn star."

Buttigieg is referring to $130,000 in payments arranged by Trump's former personal lawyer, Michael Cohen, to Stephanie Clifford, a porn star known as Stormy Daniels, who says she and Trump had an affair in 2006 after Trump married his wife Melania. Trump has denied having an affair with Daniels, but admitted in 2018 that he knew of the payments "later on."

The comments also come days after radio host Rush Limbaugh told his listeners that American voters are "still not ready to elect a gay guy kissing his husband on the debate stage president." Limbaugh said on Tuesday that Trump, who initially responded to the host's comments by saying he would not be uncomfortable with a gay president, told him to "never apologize" for his comments about Buttigieg.

"The idea of the likes of Rush Limbaugh or Donald Trump lecturing anybody on family values," Buttigieg said, before pausing for cheers and applause.

"I'm sorry, but one thing about my marriage is it's never involved me having to send hush money to a porn star after cheating on my spouse, with him or her," Buttigieg said. "So, if they want to debate family values, let's debate family values, I'm ready."

Sanders won't release more medical records

On Tuesday night, Sanders said that if anyone wants any more information about his health, they should join him on the campaign trail, where he keeps a busy schedule.

Sanders argued that the letters, including one from the attending physician at the US Capitol, amounted to a "detailed report" and, when pressed on whether he would release new details, said, "I don't think we will."

On October 1, Sanders was rushed to an urgent care facility following a grassroots fundraiser in Las Vegas after experiencing chest pains. Sanders then was taken to the hospital in an ambulance and remained there for days before returning home to recuperate.

He was back on the campaign trail about two weeks after he initially fell ill.

Klobuchar talks 'institutional racism'

Klobuchar, who before running for Senate worked as county attorney for Minnesota's largest county, defended her criminal justice record on Tuesday, telling voters in Nevada that "anyone that's worked in the criminal justice system knows there's institutional racism."

The issue is a growing one for Klobuchar: Her rise in the Democratic nominating process has coincided with more scrutiny on her record as county attorney for Hennepin County, including the case of Myon Burrell, a teenager who was sentenced to life for the killing of 11-year-old Tyesha Edwards but now, with the backing of new evidence, insists he is innocent.

"Over the years, I think we have seen just how devastating that is," Klobuchar said of racism in the judicial system. "And when I was there, I worked hard on, for instance, doing more when it came to white collar crime, doing more with drug courts. And while here were still disparities in our system, like there were any, we had still managed in the eight years to reduce the African-American incarceration rate by 12%."