Donald Trump gave West Virginia GOP Senate candidate Patrick Morrisey a boost Tuesday morning, hours before the president is to return to the state for a rally targeting Democratic Sen. Joe Manchin III.

Trump and Vice President Mike Pence have both visited the Mountain State for events aimed at firing up the conservative base and convincing swing voters their agenda needs the state’s GOP attorney general to replace Manchin. That is the message the president is again expected to deliver at a rally in Charleston.

Even before Trump boards Air Force One, he tweeted that Morrisey is “running a GREAT race for U.S. Senate.”

The tweet, however, mirrored how the president’s rallies that are ostensibly about GOP candidates have largely gone this cycle. That’s because he briefly mentioned Morrisey before praising his own time in office.

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“I have done so much for West Virginia, against all odds, and having Patrick, a real fighter, by my side, would make things so much easier. See you later,” he wrote, adding, “CLEAN COAL!!!!”

Inside Elections with Nathan Gonzales puts the West Virginia Senate race in the Tilts Democratic column.

Trump is also expected to take a few jabs at Manchin, the latest round in the often awkward dance the president and the moderate Democratic senator have engaged in over the last 19 months.

The president has at times praised Manchin for attempting to bridge the wide divide between Republicans and Democrats on many major policy issues. And Manchin has applauded some Trump moves, and even has not ruled out supporting his re-election bid.

Earlier this summer, Manchin said he is concerned that the country is becoming too clustered into Team Republican and Team Democrat, preventing major legislation from passing to solve problems both parties agree exist.

“Yeah, we’ve got to get some civility back in this place,” Manchin said then. “This place has got to work. The rule of law has to matter to all of us. The Constitution has to be our holy grail, and that has to be preserved.” Notably, he would not say whether he is concerned the president is contributing to that phenomena.

Manchin is a holdover from a different era: a Democrat from a conservative state. Trump and White House officials have targeted him and a handful of other moderate Democrats when pushing their agenda, but mostly have been unable to secure his votes on major matters.

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Perhaps that’s why Trump did not harshly attack Manchin during an April rally in West Virginia. But four months later, November’s midterms are fast approaching and control of the Senate appears up for grabs.

Trump has gotten more aggressive in his campaign-trail remarks criticizing Democratic incumbents and candidates, so the Charleston rally marks a key inflection point for the on-again-off-again relationship between the president and Manchin.

“And he does other things that I don’t like, I’ll be honest with you,” Trump said of Manchin in April. “You’re going to have a chance to get a senator that’s going to vote our program.”