MANCHESTER, N.H. — Gov. Larry Hogan is stepping up preparations for a 2020 White House bid as he moves slowly toward challenging President Trump in the Republican primary.

Maryland’s chief executive has been holding regular meetings with his political team to pore over data and mull how a campaign against Trump might unfold. Hogan also is using previously scheduled travel to more than a dozen states, including an invitation to Utah to attend Sen. Mitt Romney’s annual summit with top Republican insiders, to meet with political operatives, donors, and business leaders.

Hogan, 62, has insisted he is not interested in launching a kamikaze mission against Trump, who is popular with Republican voters and has won over some previously skeptical party bigwigs. But the governor confirmed Tuesday that his position on 2020 has shifted.

Initially just intrigued, Hogan has since moved from politely entertaining the small but vocal band of Never Trump Republicans pleading with him to run, to a more active and strategic exploration. Hogan survived a battle with non-Hodgkin's lymphoma. After being diagnosed in 2015, he underwent chemotherapy and declared himself cancer-free in late 2016.

“I am taking it more seriously and doing more things,” Hogan told the Washington Examiner in an interview as he made the rounds here for events and meetings that usually signify a presidential run. “We’re having discussions.”

Hogan was reelected overwhelmingly in the midterm elections, becoming the second Republican governor in history to win a second term in deep-blue Maryland. That feat, in the midst of a rebuke of Trump that cost the GOP control of the House of Representatives and one Senate seat, each, in Arizona and Nevada, inspired opponents of the president inside the Republican Party to recruit Hogan to take him on.

The governor’s initial response? Prop open his office door, welcome the flattery, and listen as supporters made the case.

Hogan emphasized in a February interview with the Washington Examiner that that was the extent of his involvement, saying he would not be a sacrificial lamb for Trump haters looking to hobble the president heading into the general election against the Democrats. Indeed, Hogan said then that Trump was too strong with Republican voters to justify a primary challenge.

Hogan is now more bullish on a potential 2020 bid, despite the final report from special counsel Robert Mueller letting Trump off the hook on obstruction of justice and conspiring with Russia. The governor did not hesitate to hammer the president during his swing through New Hampshire, a key early primary state. He even outlined his view of a potential primary campaign while mockingly comparing Trump to North Korean dictator Kim Jong Un.

“To change the rules and to insist 100% loyalty to the ‘dear leader’ didn’t sound very much like the Republican Party that I grew up in,” Hogan said during his trip to St. Anselm College to headline “Politics & Eggs,” a top event for presidential candidates. Hogan was referring to a resolution supporting Trump’s reelection that was approved by the Republican National Committee in January.

“Here in New Hampshire, for example, they like to be independent, they like to look at the candidates and kick the tires and meet people one-on-one. I’m pretty good at retail politics. That’s how I won my state with no money,” Hogan said during a subsequent news conference with reporters, prior to heading to the New Hampshire Union Leader newspaper for an editorial board interview and meeting with the publisher.

“There are, I think, 23 states that have open primaries of one sort or another, so independents and Democrats can cross over and vote,” he said.

[Read more: Maryland's Larry Hogan: 'I govern from the middle']

Never Trump Republicans looking for a primary challenger have usually pegged the beginning of summer, two months away, as the latest a contender could enter the race and still threaten. But Hogan said he doesn’t feel pressure to decide that soon, explaining his view that an upstart, shoestring campaign might benefit from making a late, splashy entrance. His confidence is rooted in the president's anemic standing nationally, with an approval rating generally in the low 40s.

In that regard, he cited the filing deadline for the New Hampshire primary, Nov. 15, as a likely drop-dead date.

The question is whether political atmospherics change, creating legitimate opportunities to dethrone Trump. Tom Rath, a veteran GOP operative here aligned with former Ohio Gov. John Kasich — himself considering a bid — is no Trump fan. But he conceded most rank-and-file Republicans back the president, especially with a booming New Hampshire economy at full employment.

Any hope a Republican insurgent has to use New Hampshire as a springboard against Trump would rely heavily on independents, who can participate in primaries. But with a competitive and crowded Democratic field that could attract many of those voters, that high wire strategy could prove more of a long shot than usual.

“Self-styled Republicans are, at the moment, pretty much in lockstep,” Rath said.

[Opinion: 2020 warning: Trump 'least popular president to run for reelection in the history of polling']