Tucker Carlson sat down for a wide-ranging interview with President Trump during his trip to Michigan, where he discussed wiretapping, his tax returns and ObamaCare.

Regarding ObamaCare, Carlson asked whether Trump would deliver on his campaign promises of lower costs and better access for many in the country who need it, in light of conservatives' criticisms of the new legislation in its current form.

Trump said that if he had a plurality in the Senate, he could engineer a wider-ranging overhaul of the American health care system, but reiterated a point Speaker Paul Ryan (R-Wis.) made, in that certain items cannot be passed with a simple majority.

"I think we're going to have negotiations-- we only have 52 [Republicans], a two-vote margin," Trump said. "We're never going to have a Democratic vote."

.@POTUS: "If I had the greatest bill in the history of the world, [@TheDemocrats] would not vote for us b/c they hate the @GOP." #Tucker pic.twitter.com/b5TCJhLvXr — Fox News (@FoxNews) March 16, 2017

But, Trump said that the bill that comes to his desk must meet his expectations: "If we're not going to take care of the people, I'm not signing anything."

Trump said that President Obama may have foreseen the Affordable Care Act's shortcomings, saying Obama knew 2017 would be the law's "worst year" and he would be out of office by then.

"ObamaCare is imploding, it's a disaster," he said.

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Trump also slammed journalist David Cay Johnston, who said Tuesday he acquired part of the president's 2005 1040 tax form.

"I don't know where they got it," Trump said. "This guy's been following me for 25 years. He's not much."

Trump said whoever leaked his tax return to Johnston broke the law and that the situation is "a disgrace."

.@POTUS responds to the release of his tax return. Watch the @TuckerCarlson exclusive, tonight at 9pm ET. pic.twitter.com/WXMxMoKcVt — FoxNewsInsider (@FoxNewsInsider) March 15, 2017

Trump also said the tax system is unfair to many Americans, but said that ObamaCare replacement "has to come first."

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Carlson asked the president about his widely-disseminated tweet in which he said President Obama may have wiretapped Trump Tower.

.@POTUS on wiretapping evidence: "We're in the process of putting it together and I think it's going to be very demonstrative." #Tucker pic.twitter.com/6RzEr8UXoE — Fox News (@FoxNews) March 16, 2017

"Why not wait?" Carlson asked. "You're the president. You have the ability to gather all the evidence you want."

Trump pointed to a New York Times story published about the campaign on Inauguration Day that used the term "wiretap," and also said several news programs floated reports about such surveillance.

Regarding his penchant for releasing information via social media, Carlson asked whether his Twitter messages are vetted by someone before he tweets.

Trump said that sometimes they are reviewed by his advisers, but added that many in the "fake press" do not cover his administration fairly, and that he can speak directly to the public through Twitter without the media's filter.

"I might not be talking to you right now as president if I didn't have a way of getting the word out," he said.

Watch more of Trump's interview with Tucker Carlson below: