Former New York City Mayor Mike Bloomberg on Tuesday took aim not only at President Trump, but also at some of his potential rivals for the Democratic presidential nomination and progressive Rep. Alexandria Ocasio-Cortez, during a stop in the state that holds the first primary in the race for the White House.

Speaking with reporters following a tour of a manufacturing plant in Nashua, Bloomberg criticized the "Green New Deal," a bill being pushed by Ocasio-Cortez and other progressive lawmakers that would eliminate much of the United States’ fossil-fuel consumption.

“You have to have realistic things; we are not overnight going to change everything we do,” Bloomberg said. “People aren’t going to overnight give up their jobs if those jobs happen not to be on the side of the Green New Deal.”

The billionaire media mogul, who has contributed millions to the battle against climate change as well as the push for gun safety, called for “doing things intelligently.”

“One of the things my foundation has done: We’ve funded Sierra Club. They’ve already closed half of all the coal-fired power plants in the country. That’s reduced greenhouse gases by 18 percent,” he said.

Earlier, at an address on climate change at the New Hampshire Institute of Politics in Manchester, the possible White House contender noted that “I’ve already begun working on putting together the details of what I believe a Green New Deal should look like.”

And he emphasized that “whether I run for president or not, I will work to ensure that fighting climate change, and spurring economic development in areas that have depended on fossil fuels, is a top priority for the Democratic nominee.”

Bloomberg, a Republican-turned-independent who returned to the Democratic Party just last year, is seen as more moderate than most in the emerging field of 2020 presidential contenders.

Bloomberg, who turns 77 next month, also criticized a new push by Sen. Kamala Harris of California for a “Medicare-for-All” single-payer health care plan. The California Democrat and declared presidential candidate said Monday while campaigning in Iowa that she’s willing to end private insurance to make ‘Medicare-for-all’ happen.

“I think you could never afford that; you’re talking about trillions of dollars,” Bloomberg told reporters.

“To replace the entire private system where companies provide health care for their employees would bankrupt us for a very long time. It’s just not a practical thing,” he added.

Bloomberg also dismissed a proposal by another presidential contender – Democratic Sen. Elizabeth Warren of Massachusetts – to place a wealth tax on the super-rich.

“No. 1, I think the Constitution lets you impose income taxes only, so I think it’s unconstitutional,” he said. “No. 2, I don’t know of any country that’s done that. People earn money, they pay their taxes and then they don’t expect the government to come back and take some of it away.”

Bloomberg also criticized a longstanding push by independent Sen. Bernie Sanders of Vermont – who’s mulling a second straight bid for the Democratic nomination – to make tuition free for all in-state students attending community colleges. Sanders’ plan also calls for free-tuition for students at four-year public colleges whose families earn under $125,000 a year.

“Free college tuition would be a nice thing to do, but unfortunately your professors want to get paid,” Bloomberg said.

Bloomberg also targeted fellow billionaire Howard Schultz, the onetime Starbucks CEO now considering an independent run for president. Bloomberg joined a chorus of criticism by Democrats, who fear that such an independent run could help Trump cinch re-election in 2020.

At the start of a speech at the New Hampshire Institute of Politics, Bloomberg said that Trump “failed at business and now I think it’s fair to say he’s failing at governing.”

Slamming the Republican president over the 35-day partial shutdown of the federal government, Bloomberg said, “The government shutdown was an utter failure of executive leadership, and I think it’s an example of just totally incompetent management that needlessly hurt millions of people.”

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“I’m glad the shutdown is over for now, but the American people will continue paying a steep cost for White House incompetence, because the president is fixated on a wall we don’t need instead of real challenges we face,” he added.

Bloomberg also criticized the president as a climate change denier, saying “his own administration produced a damaging report showing that we face what they called ‘substantial damage to the U.S. economy, environment, and human health from climate change.’ And you know what the president said in response? ‘I don’t believe it.’”

And he argued that “the president’s EPA (Environmental Protection Agency) has been waging an assault on clean air and water protections.”

Later, he told Fox News “what the president is doing now is just terrible for America and the world.”

Bloomberg’s trip to the Granite State sparked more speculation regarding his potential presidential bid. Acknowledging his visit, he joked “nothing political. I always come to New Hampshire in the winter when it snows.”

Later, he said he would decide on a White House run by the end of February.

The Republican National Committee called the potential candidate "delusional.”

"Michael Bloomberg's visit to New Hampshire signals just another delusional Democrat mulling a bid for what will be a circus of a 2020 presidential primary. But Bloomberg's out-of-touch agenda of gun control, climate control and raising taxes would only take us backward as a nation, and Granite State voters aren't buying it,” RNC spokeswoman Mandi Merritt said.

Bloomberg arrived in New Hampshire on Monday, holding private meetings with top political leaders including longtime state Democratic Party chairman Ray Buckley. He also met with entrepreneurs.

His speech on climate change, which New Hampshire Institute of Politics executive director Neil Levesque said was the most well attended ‘Bookmark Series’ event ever, drew a healthy crowd of national reporters and cameras.

Asked during a question and answer session following his remarks what he would do with his philanthropic foundation if elected president, Bloomberg said, “I would put the foundation into a blind trust. I did that while I was mayor.”

“Every banker’s rushing to call. Don’t call. It’s not for sale,” he joked.

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Later in the day, Bloomberg visited Harvey’s Bakery and Coffee Shop in Dover, another must stop for White House hopefuls. He was hosted there by Bill Shaheen, a longtime attorney and husband of Sen. Jeanne Shaheen, who’s also a Democratic National Committeeman.

Bloomberg wrapped up his New Hampshire swing in Concord Tuesday night, at a house party hosted by Democratic activists.