Florida Gov. Ron DeSantis, now officially a candidate for president, is no longer tiptoeing around former President Donald Trump -- nor is he being shy about his plans to flex the powers of the presidency like never before if he wins the White House.

DeSantis has filled the hours after his botched Twitter launch by taking his message to the familiar comforts of the conservative airwaves, where, in a dozen interviews, he has assailed Trump as fiscally irresponsible and a supporter of amnesty for undocumented immigrants. He said Trump's Covid-19 mitigation policies "destroyed millions of people's lives" and told Fox News his "day one" priority would be to fire the former president's handpicked FBI director, Christopher Wray.

Trump "is a different guy today than when he was running in 2015 and 2016," DeSantis told Tennessee conservative talk radio host Matt Murphy, adding, "I don't know what happened to Donald Trump."

The sharpening of attacks against Trump -- whose endorsement DeSantis once sought and campaigned on in his 2018 race for governor -- comes after months of subtle digs at the former president's stint in the White House. Throughout Trump's four years in office -- of which DeSantis served almost two years in Congress and two years as a closely aligned governor -- and in the years since, the Florida Republican has never before levied such direct and public criticism of the man he now hopes to supplant as the leader of the GOP.

Now, DeSantis is making the case that he is better suited to deliver on the promises that Trump himself failed to see through.

Doing so will require pushing the limits of the executive branch like never before, DeSantis has suggested in multiple interviews in the past 24 hours. He told conservative radio host Mark Levin that he had studied the US Constitution's "leverage points" and would use his knowledge to exercise the "true scope" of presidential power.

"You've got to know how to use your leverage to advance what you're trying to accomplish," DeSantis told Twitter CEO Elon Musk during their conversation.

Trump has pushed back against these missives by poking fun at the glitches that marred the Florida Republican's entrance into the race and suggesting DeSantis isn't ready for the Oval Office.

"'Rob' DeSanctimonious and his poll numbers are dropping like a rock. I would almost be inclined to say these are record falls," Trump posted on Truth Social on Thursday. "The question is Rob just young and inexperienced and naive or more troubling, is he a fool who has no idea what the hell he's doing? We already have one of those in office, we don't need another one. We need MAGA."

DeSantis' vision for the executive branch is seemingly at odds with the Republican Party's traditional adherence to the principles of limited government. Many Republicans often accused former President Barack Obama of extending his powers unconstitutionally and DeSantis himself wrote an entire book in 2011 based on that perception. But it is an approach Republican voters have come to expect from their elected leaders in the years since Trump emerged and dispensed with governing norms.

It is also in keeping with how DeSantis has led from Tallahassee. As governor, DeSantis has systematically strengthened the office of the governor and stretched its constitutional powers in ways that no previous executive has. He seized control of the state's environmental protection agency, deployed the state's police force in novel ways, created a law enforcement team to monitor voting, removed a democratically elected local prosecutor and orchestrated a takeover of a small liberal arts college.

DeSantis has treated state bureaucracies that previously operated independently as extensions of his executive offices. He has stocked state regulatory boards with like-minded political appointees, who have followed his lead in banning gender affirming care for minors and extending restrictions on school lessons about sexual orientation and gender identity. He has punished Disney, the tourism engine of the state and its most iconic business, for challenging him over those restrictions, and forced state lawmakers to pass a new congressional map drawn by his office.

"I may have earned 51 percent of the vote, but that entitled me to wield 100 percent of the executive power, and I resolved to use it to advance conservative principles," DeSantis said at an event in Wisconsin on May 6.

In his latest book, "The Courage to Be Free," DeSantis described his extraordinary use of state power as deliberate and tactical. He wrote that before taking office he had studied an "exhaustive list" of the governor's constitutional authority and would use "every lever available to advance our priorities."

"What I was able to bring to the governor's office was an understanding of how a constitutional form of government operates, the various pressure points that exist, and the best way to leverage authority to achieve substantive policy victories," he wrote.

Now, DeSantis' opening message to Republican voters is that he would bring that methodical precision to the White House in ways that past executives -- Trump included -- failed to.

"Presidents have not been willing to wield Article Two power to discipline the bureaucracy," DeSantis said. "I'll come in and on day one we'll be spitting nails."

Among his top priorities, DeSantis said, would be to "re-constitutionalize" the federal government, which he described as a plan to "discipline the bureaucracy" and agencies that he saic are "detached from constitutional accountability."

He would dispel with the longstanding tradition that government institutions like the US Department of Justice operate independently from the president -- embracing a philosophy that Trump often governed by but never articulated so succinctly.

"Republican presidents have accepted the canard that the DOJ and FBI are quote, independent," DeSantis said. "They are not independent agencies. They are part of the executive branch. They answer to the elected President of the United States."

DeSantis also touched on pardons, when asked about whether he would consider the cases of those who face charges related to the January 6, 2021, insurrection at the US Capitol, as well as whether he would pardon Trump should he be charged federally.

He said he would look at all cases of "disfavored treatment based on politics or weaponization."

"The DOJ and FBI have been weaponized. On day one, I will have folks that will get together and look at all these cases, who, people are victims of weaponization or political targeting, and we will be aggressive and issuing pardons," DeSantis told "The Clay Travis & Buck Sexton Show" Thursday.

At the same time, DeSantis said pardons would be looked at individually, not necessarily to an entire group.

"We will apply relief as appropriate," DeSantis said. "It will be done on a case-by-case basis."

Those remarks drew an immediate rebuke from the Democratic Party, alerting in a news release that DeSantis was "spending his first day as an official presidential candidate promising to consider pardons for some January 6 insurrectionists and convicted criminals who attacked law enforcement."

In his private pitch to donors, Desantis has noted that Trump, who has already served one term, would be a lame duck president if elected. Since launching his candidacy Wednesday, DeSantis has more publicly laid out why that should give Republicans pause.

"I understand, and all your listeners should understand," DeSantis said on Levin's show, "that if we do everything right, if we're disciplined, if we're strong as anyone could be, it still takes a two-term project."