WINDHAM, N.H. — As he called into Joe Piscopo’s radio show from a diner last week, and then trash-talked both political parties over a bacon-and-egg-white omelet, Corey Lewandowski demonstrated why he’d be a fitting Republican Senate nominee on the 2020 ticket with President Trump — and why that prospect appalls New Hampshire’s more traditional G.O.P. leaders.



Mr. Lewandowski, the president’s former campaign manager, sounded every bit like his pugilistic political patron as he unleashed a blur of attacks and insinuations in a manner reminiscent of an out-of-control garden hose.

He called Senator Jeanne Shaheen, the Democrat whose seat he is considering running for, “a partisan hack.” He accused Judd Gregg, a well-liked former Republican senator and governor, of taking “a military deferment for bed-wetting” to avoid serving in Vietnam. And he savaged New Hampshire’s mainstream conservative leaders, saying they “ran this state into the ground” and left the party with no congressional seats and out of power in the state legislature.

Welcome to the era of the would-be Trump Candidate.

One year after the president waded into Republican primaries from Florida to Kansas, propelling his favorites to win nomination contests for Senate and governor, Mr. Trump is now going even further in his attempt to reshape the G.O.P. in his image. He is nudging one of his most controversial lieutenants to run for the Senate in one of the few states where his party has a chance to pick up a seat in 2020. At an arena rally in Manchester, N.H., last month , Mr. Trump said Mr. Lewandowski was “fantastic” and would be “tough to beat,” stopping just short of endorsing him.

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Yet Mr. Lewandowski’s prospective bid has unsettled an array of powerful New Hampshire Republicans, including Gov. Christopher T. Sununu, who are not keen on elevating a political operative-turned-Washington consultant as their Senate standard-bearer.