Mike Bloomberg in Politico.com

On Energy & Oil: $218M effort led to closure of 282 coal-fired power plants

For instance, Bloomberg has contributed $218 million for clean-energy efforts that, among other results, have led to the closure of 282 coal-fired power plants. But he does not oppose, at least in the short term, other fossil fuel use--and that's not good enough for climate change activists

On Government Reform: Fund voter registration in FL, WI, OH, MI, and PA

"Whoever the nominee is likely won't be decided until late into 2020, and whoever that nominee is will face a very large and well-funded campaign in waiting," a Bloomberg adviser, who led Obama's battleground effort in 2012, told POLITICO last month.

"As we looked at the gaps in the current ecosystem, we said, 'Could we set something up right now that could provide the infrastructure, provide the data and technology to whomever the eventually nominee is so they're not at such a disadvantage once the primary is over?'" the adviser said. "We can."

On Health Care: We can never afford to replace employer-based health system

The billionaire slammed a Medicare-for-All proposal floated by 2020 candidate Sen. Kamala Harris (D-Calif.), saying the country could "never afford" replacing the employer-offered health care system in its entirety.

The Republican-turned-independent-turned-Democrat supports Medicare for those without health insurance, but he does not want to do away with the employer-provided model.

Bloomberg said, "I'm a little bit tired of listening to things are pie in the sky, that we never are going to pass, are never going to afford. I think it's just disingenuous to promote those things. You've got to do something that's practical."

On Principles & Values: American Cities Initiative philanthropies gave away $6.4B

[Via Bloomberg Philanthropies], Bloomberg's giving covers five major areas--environment, public health, government innovation, the arts and education--and last year totaled $787 million, making him the nation's second-most generous philanthropist behind Amazon founder Jeff Bezos.

Through one of his biggest programs, the American Cities Initiative, Bloomberg has helped municipalities and activists grapple with everything from climate change to guns to obesity. The initiative is an outgrowth of Bloomberg's time as New York City mayor and has helped sow goodwill with mayors and former mayors throughout the country, giving him possible entr‚e to a layer of local political support that conventional candidates lack.

On Tax Reform: Progressive tax yes; wealth tax no

He calls for a more progressive tax rate, but sees the wealth tax advocated by Sen. Elizabeth Warren (D-Mass.) as going too far. "I believe that that plan should be bold and ambitious and most importantly achievable," Bloomberg said. "You've got to do something that's practical."

Warren hit back at Bloomberg's claim that her wealth tax proposal is "probably unconstitutional." The Massachusetts Democrat said in a tweet, "Billionaires like Howard Schultz and Michael Bloomberg want to keep a rigged system in place that benefits only them and their buddies. and they plan to spend gobs of cash to try and buy the presidency to keep it that way. Not on my watch."

On Tax Reform: The wealthy prefer the current rigged system

He calls for a more progressive tax rate, but sees the wealth tax advocated by Sen. Elizabeth Warren (D-Mass.) as going too far. "I believe that that plan should be bold and ambitious and most importantly achievable," Bloomberg said. "You've got to do something that's practical."

Warren hit back at Bloomberg's claim that her wealth tax proposal is "probably unconstitutional." The Massachusetts Democrat said in a tweet, "Billionaires like Howard Schultz and Michael Bloomberg want to keep a rigged system in place that benefits only them and their buddies. and they plan to spend gobs of cash to try and buy the presidency to keep it that way. Not on my watch."