GRINNELL, Iowa -- Businessman Tom Steyer began his Sunday CNN night town hall in Iowa by challenging fellow billionaire Michael Bloomberg, who appears poised to join the Democratic presidential primary, to support a wealth tax.
Steyer also promised immediate action to combat the climate crisis, promising to invoke "emergency powers" on the first day of his presidency as a means of tackling the issue.
But the longtime Democratic donor and impeachment advocate also cast himself as a moderate in opposition to the progressive frontrunners, Sens. Elizabeth Warren and Bernie Sanders, with his support for a public health insurance option, suggesting it would be less disruptive to implement than the sweeping "Medicare for All" plan the two progressive senators support.
Here are four takeaways from Steyer's town hall:
Steyer puts Bloomberg on the spot
Steyer took early aim at Bloomberg, saying the former New York City mayor should either get on board with a wealth tax or think twice about pursuing the Democratic nomination.
"Unless Mr. Bloomberg is willing to accept a wealth tax, I don't believe he can be an appropriate nominee for the Democratic Party," Steyer, who supports the policy, said early on in the evening.
He also pledged to "undo" all of the tax cuts given to the wealthiest Americans and corporations over the past four decades.
"The distribution of wealth across society is an absolute scandal," he said.
Bloomberg on Friday filed to run in Alabama's Democratic presidential primary in 2020, in the clearest sign to date that the former mayor is seriously considering following through with something he has been weighing for weeks.
Steyer: Judge me by how I handled scandals
In South Carolina, a Steyer adviser resigned after being outed for accessing volunteer data compiled by Sen. Kamala Harris' campaign.
In Iowa, a Steyer adviser resigned after being accused of offering money in exchange for endorsements.
But on Sunday night, Steyer argued that his reaction to those scandals -- and not critics' suggestion of a culture of impropriety -- is what voters should focus on.
"Unauthorized things happen (in campaigns) and the question is what you're going to do about them," he said. "In both those cases, we did exactly what I think is appropriate. We went in, we figured out what happened, we took action."
By immediately acting to secure resignations from the individuals accused, Steyer said, his campaign was actually demonstrating a unique strength.
"That's exactly what you look for in an organization -- that you have rules that are enforced by the organization when something that is not proper occurs," Steyer said.
"You deal with it with the highest possible integrity, you actually walk the walk of doing the right thing, and then you move on."
Steyer breaks with progressive leaders on health care
"Medicare for All" is not for Tom Steyer.
The billionaire businessman said he would prefer to build on the current system, as it exists under the Affordable Care Act, and push for a public option, or a government-backed insurance plan.
The issue, he argued, was one of choice.
"I happen to be one of the people who believes in a public option, giving people the option basically of joining Medicare, but allowing 160 million people to make the decision for themselves," Steyer said.
Steyer also pointed to organized labor, and union members who have negotiated for their insurance, as a reason he would shy away from a more radical shift.
"I don't think it's right for the government to tell them that we're going to scrap a 75-year-old system. If you like it, keep doing it," he said. "If the public option is cheaper and better for you, then you can go to your employer and say pay me the money you're spending on my health care, I'll buy the public option."
Climate change comes first in a Steyer White House
How is Tom Steyer different from his primary rivals when it comes to climate change?
The answer, he said, is simple: It is his "number one priority" -- taking precedent over any and all other issues.
Steyer on Sunday said he would declare a state of emergency on climate on his first day in office and use the emergency powers of the presidency "to make changes immediately."
He also pledged to demand Congress to pass a version of the Green New Deal during his first 100 days in office.
"I've spent over a decade fighting oil companies and beating them at the ballot box. I've led the charge for clean energy across the country at the ballot box," Steyer said. "I've worked to stop pipelines. I've worked to stop fossil fuel plants. We're talking about the future, but you can look at my history and know that this is something that is an absolutely top priority for me."
Steyer added he does not fly private, and said he hopes the rest of the Democratic field would promise to forswear it too.