Virginia Gov. Ralph Northam gestures as he delivers his State of the Commonwealth address Monday in Richmond. (Steve Helber/AP)

House Speaker Kirk Cox (R-Colonial Heights) marched over to Democratic Gov. Ralph Northam's office Tuesday morning to tell him the week-old bipartisan vibe in the Capitol is hanging by a thread.

Plans to work together on issues such as criminal justice reform and even Medicaid expansion are suddenly in doubt because of what Republicans saw as an overly partisan speech by Northam to the General Assembly on Monday night.

"Frankly, that speech last night truly set us back," Cox said at a hastily assembled news conference Tuesday morning.

The dust-up signals the fragile dynamics in Virginia's closely divided legislature, where Republicans long used to dominance are reckoning with newly powerful Democrats.

Northam took office just this weekend, calling on Virginia to set an example for the nation of how to work together and get things done. Republicans had welcomed him as a homegrown politician they could trust — a big change from his predecessor, Terry McAuliffe, whom they saw as a Democratic operative.

Republicans had even prepared a response to Northam's Monday night speech that expressed eagerness to find common ground, but they tore it up once they saw his actual words. In the speech, Northam drew cheers from Democrats for citing a series of campaign promises such as expanding women's access to abortion and expanding Medicaid.

As the litany went on, Republicans sat in increasingly stony silence. When they finally rose in support of easing student debt, Northam quipped that they needed to stretch after sitting so long.

Afterward, Cox asked to meet with him privately.

"I was very blunt with him," Cox said Tuesday morning, shortly after the one-on-one at the governor's office. "I shared personally how disappointed I was."

Northam's office had no comment on the meeting. A spokeswoman defended his speech as aimed not at partisan issues, but at "real problems that affect real people." Bipartisanship, spokeswoman Ofirah Yheskel said, "does not mean sweeping big issues under the rug because common ground has been hard to find in the past."

Richmond is a relational town, and both Republicans and Democrats have been counting on widespread personal affection for Northam to ease political gridlock. While McAuliffe tried and failed to get Medicaid expansion for four straight years, Republican leaders are no longer shutting the door on some form of expansion.

That's partly because of the huge Democratic gains in last fall's elections. Voters reshaped the House of Delegates, reducing Republicans to the barest of majorities — 51-49 — which they maintained only after one tied race was decided in their favor by random drawing.

Saturday's inaugural speech was the place for Northam to take a victory lap in front of the whole world, Cox and other Republicans said. They saw the Monday night address, by contrast, as a family affair. They expected Northam to include more nods to areas of easy agreement with Republicans — such as addressing the opioid crisis — as well as to credit Republicans for work they've done on the budget and economic development.

But partisan tensions had flared even before Northam's speech. On Monday, a Senate committee killed Democratic bills aimed at gun safety, including one providing for universal background checks for anyone who purchases a gun. All had been Northam priorities, and on Monday night he scolded the committee for nixing them.

On Tuesday, Democrats played hardball of their own in the Senate. Aiming to pressure a Republican senator into supporting Medicaid expansion, Democrats made good on a threat to kill a bill intended to help a shuttered hospital in his poor Southwest Virginia district.

"I have never intimated to any of you all, nor have I ever told you, 'Unless you do something for me, I will kill your bill,'" Sen. William Stanley (R-Franklin) said after his measure failed on a 30-10 vote. Nine Democrats had voted along with all 21 Republicans, but Stanley was two votes short of the supermajority he needed for emergency legislation.

Stanley was trying to renew state certification for Patrick County Hospital, which closed last year, in hopes that a new operator would come forward. "I'm angry. And I'm ashamed of you," he said.

Democrats, who need support from two Republicans to get Medicaid expansion out of the closely divided Senate, said their goal was the same as Stanley's — only on a larger scale.

"I'm angry also," said Sen. Janet D. Howell (D-Fairfax). "I'm very angry that I have constituents — yes, even in Northern Virginia, even in wealthy Fairfax County and Arlington County — that have no health care. They're suffering. A few of them died. . . . I think we need to get together to figure out a way we can provide health care throughout the commonwealth and not pick one small community."

After the vote, Stanley said Democrats have turned the hospital into a pawn in the Medicaid fight.

"I'm heartbroken that they would try to pull this stunt on something that has nothing do with what they're trying to achieve," Stanley said in an interview.

Minority Leader Richard L. Saslaw (D-Fairfax) seemed to acknowledge that his vote against Stanley's bill had been "a political vote." Seeking to defuse the tension, he also suggested that the measure might be revived, perhaps as an amendment to another bill.

But Republicans took retribution by calling up bills that had passed earlier, stripping out the ones sponsored by Democrats and putting those aside for the day.

Democratic leaders in the House said that they want to work across the aisle but that they interpret last fall's election as a message sent by Virginians who want a higher minimum wage, an end to workplace discrimination and better gun control, among other priorities.

"While bipartisanship and civility have their appropriate place and they're something that we embrace, we also have to consider these bills and take positions on bills," House Minority Leader David Toscano (D-Charlottesville) said.

Sen. Majority Leader Thomas K. Norment (R-James City) said he had heard the words "comity, collaboration and cooperation" batted around for days. "Somehow those words are already starting to ring hollow," he said.