President Trump harkened back to his days on "The Apprentice" Wednesday, telling Republican senators that if they didn't repeal and replace Obamacare they could hear, "You're fired" at their next election.

"Inaction is not an option, and frankly, I don't think we should leave town unless we have a health insurance plan," he said at a lunch with Senate Republicans hastily called after they failed to find 50 votes to move forward with two different approaches to Obamacare earlier this week.

The move was fraught with risk. Senators do not take kindly to being lectured, especially by someone who has shown little engagement with policy details at stake in the healthcare fight. In the last two days, Trump has called for repeal and replace, full repeal, and letting Obamacare collapse under its own weight.

Trump has also called for reforms that most experts do not believe can be enacted through the reconciliation process Republicans are relying on to bypass Democratic filibusters. But after Senate Republicans left their lunch with the president, they revived their push for a vote next week on a partial repeal and replace bill (a Wednesday evening meeting of senators giving it one more try had been scheduled before the White House event).

"Any senator who votes against starting debate is really telling America that you're fine with Obamacare," Trump told the assembled Republicans.

It was an unusual and maybe unprecedented display for a president to call members of his party on the carpet so publicly. Such admonitions might take place privately in the Oval Office but seldom in front of the television cameras.

Trump invited Senate Republicans to lunch at the White House after they failed to come up with the votes for either a reconciliation bill overhauling Obamacare or advancing clean repeal of the healthcare law.

Congress passed clean repeal in 2015 only to have it vetoed by President Obama a month later. Trump not too subtly pointed out that the change in president might be the difference.

"I have pen in hand, believe me," he said. "I'm sitting in that office. I have pen in hand. You never had that before."

Trump also needled the Republican holdouts, sometimes eliciting laughter from the room and other times leading to some awkward moments.

"The other night I was surprised when I heard a couple of my friends — my friends, they really were and are" were coming out against the Senate GOP healthcare bill, he said. "They might not be very much longer, but that's okay. I think I have to get them back."

Trump turned to Sen. Dean Heller of Nevada, one of the most vulnerable Republicans running for re-election to the upper chamber in 2018, and said he was the one party leaders had been worried about.

"You weren't there. You're going to be," Trump told Heller, adding, "He wants to remain a senator, doesn't he?"

The comments were delivered in a joking matter, but they come after reports Trump is willing to support primary challengers to Republican lawmakers who cross him regularly, such as Sen. Jeff Flake, R-Ariz.

When the House finally passed its healthcare bill after early setbacks, Trump had a Rose Garden celebration for Republicans in that chamber. Vice President Mike Pence, Health and Human Services Secretary Tom Price and Office of Management and Budget Director Mick Mulvaney, a former House Freedom Caucus member, were dispatched to negotiate with recalcitrant lawmakers.

Trump ran as a consummate negotiator himself, the man behind The Art of the Deal. Nevertheless, his tenuous grasp on healthcare policy and the motivations of the various Republican factions has inhibited his ability to cut a deal, though GOP whip team members emphasize the president did whatever they asked him to do when it came to cajoling lawmakers.

Yet, on Wednesday, Trump cut through the minutiae and as titular head of the Republican Party reminded senators of the promises they had made to rank-and-file GOP voters for seven years.

Earlier in the day, Trump exhorted Republicans on Twitter that they "MUST keep their promise to America!"

Soon, we will see if the president's act of showmanship translates into an act of leadership.