Three-term Republican State Representative Geoff Diehl of Whitman, the first elected official from Massachusetts to endorse Donald Trump in 2016, is scheduled this evening to officially announce that he is seeking the GOP nomination to run against the state’s senior U.S. senator, Democrat Elizabeth Warren.

Whomever the Republicans choose to contest Warren’s seat – and there are four probable candidates, including Diehl ­– could have an effect on Republican Governor Charlie Baker’s 2018 reelection effort. 

Baker, like his three most recent Republican predecessors (Bill Weld, Paul Cellucci, and Mitt Romney) needs a meaningful number of Democrats to cross party lines next November to reinforce Republicans, who for a generation have been a numerical minority.

According to this line of thinking, if the 2018 Senate race were to turn into a contest between the Trumpian worldview and Democratic-progressive values as personified by Hillary Clinton, Bernie Sanders, and Warren, a possible blue wave would swamp Baker.

Could Diehl be a destabilizer?

I spoke with several people close to Baker. All declined to characterize Diehl as such.

“The nomination to unseat Senator Warren is a party affair. There are many strains of thought among local Republicans, and a hard-fought primary will yield the strongest candidate to challenge a formidable foe,” one Baker loyalist said, speaking on the condition of anonymity in order to “maintain party harmony.”

Go a rung down the political organization chart, and you find a whiff of guarded candor.

“Diehl is a classic right-wing Massachusetts Republican,” said a Baker operative who works in the trenches. “Geoff led the fight to torpedo the proposed increase in the Mass. gas tax. That was a Republican idea that had considerable Democratic support, especially in the suburbs. But Diehl, at this point in time anyway, is a Trump true believer. Look at the way he went after Warren when she published her book.”

The reference is to Diehl’s attack that Warren should be working for the best interests of statewide voters, not writing political manifestos while in office.

Diehl’s zing prompted shouts of joy among conservative radio talk show audiences but triggered considerable progressive outrage – at least as measured on social media.

A spokeswoman for the Diehl campaign said the thrust of his candidacy could be simply stated: "Put the people of Massachusetts first."

Last week, more moderate Republicans who nevertheless sport a conservative strip reacted favorably when former Mitt Romney aide and Scott Brown campaign manager Beth Lindstrom confirmed that she was actively exploring a primary bid.  

After reports of Lindstrom’s interest surfaced, Politico’s Massachusetts Playbook reported: “Lindstrom has apparently been laying the groundwork for a run by meeting with party leaders, former colleagues, and elected officials. And she has already locked down the support of high-profile Mitt Romney campaign alums Eric Fehrnstrom, Peter Flaherty, Gail Gitcho, and Rob Willington, who all say they’re willing to join her team.”

 Within the insular world of local GOP activists, Lindstrom’s ability to field a seasoned campaign team is seen as a huge plus.

“Lindstrom is a dream candidate for the state party,” said political scientist Peter Ubertaccio, dean of Stonehill College’s School of Arts and Sciences. “She’s the adult of the declared Senate candidates: a well-regarded, successful businesswoman with ties to both Scott Brown and Mitt Romney. She complements Baker in a way that won’t turn off the voters the Governor needs to keep."

Ubertaccio continued, “Diehl’s explicitly pro-Trump campaign will cause an aggressive reaction, won’t get Diehl any closer to a general election victory, and risks alienating Democratic and independent voters against the entire GOP ticket. Baker will have to keep Diehl at arms length for fear of alienating those many Democrats and un-enrolled voters who like Baker but hate Trump. With Lindstrom, Baker and the state GOP get a better deal.”  

With Clinton sidelined and Sanders more of a cultural than political force, defeating Warren would be a talismanic national Republican moment.

It’s also a long shot. Warren remains a favorite Democrat of Las Vegas bookmakers, some of whom say she has – odds-wise, at least – a good shot at being elected president.

There are two other Republicans to consider: John Kingston, a wealthy businessman and long-term party contributor, and V.A. Shiva Ayyadurai, a Belmont entrepreneur with four MIT degrees who Boston Magazine dubbed “the shock candidate,” because of his seeming willingness to go to the right of Diehl.