Behind the scenes, however, Greitens and his wife worked feverishly to stanch the bleeding and save his political career.
Their efforts came as St. Louis circuit attorney Kim Gardner announced a formal investigation into the matter, potentially extending the life of the controversy.
"The governor is very confident he will be cleared in any investigation," Greitens' lawyer, James Bennett, said. Privately, Greitens sought to assure the political community of the same.
The governor convened a conference call Thursday with donors, and Eric and Sheena Greitens later spent the afternoon dialing Senate and then House lawmakers, reiterating their public statements and their resolve to move forward. CNN was informed of the calls by multiple lawmakers and other GOP sources.
State Sen. Gary Romine, one Republican who has publicly called for an investigation into Greitens, told CNN that when the governor called him on Thursday, he went as far as to vow that no other allegations would come to light.
Greitens wanted to "make sure that I heard from him personally that those allegations are false," Romine said. "He reaffirmed that they are false, and there will be nothing else coming out in the future -- no additional stories."
While Romine said that "all people are innocent until proven guilty" and that he is eager for the investigation to commence, he also suggested that his patience is not limitless.
"At some point, if there's not a way to squash this or get it off the radar and out of the system, obviously at some point, it's going to be important for him to consider resignation," he said.
State Sen. Doug Libla, another Republican who lobbied for an investigation into the governor, told CNN that Greitens called him Thursday and that the two men had a "short conversation."
"I told him I was looking forward to the investigation and look at the evidence and see at that time how the case should move forward," Libla said, but declined to detail what Greitens said in response.
A state House Republican, who did not wish to be named publicly, received a call from the governor and his wife on the phone together. The governor apologized for his affair, the Republican said, but also denied any misconduct beyond that — instead blaming those allegations on "liberal media and Democrats trying to destroy him." The lawmaker pushed back, expressing disappointment at the governor's excuse.
"There were other things I wanted to ask him or say, but couldn't do it with (Sheena) on the line," the House Republican added. "It was incredibly awkward."
But their united front to some lawmakers was consistent with the public response by Eric and Sheena Greitens, who acknowledged the affair in their initial statement as "a deeply personal mistake" by the governor.
"Eric took responsibility, and we dealt with this together honestly and privately," they said in a joint statement released Wednesday. "While we never would have wished for this pain in our marriage, or the pain that this has caused others, with God's mercy Sheena has forgiven and we have emerged stronger."
The question now facing the governor is whether Republican lawmakers will forgive him, too. It is not simply a cut-and-dry partisan matter, with many state lawmakers of Greitens' own party nursing frustrations over his aggressive governing style — which has often involved the statehouse as his political punching bag. A pro-Greitens group, A New Missouri, has also run ads targeting specific Republican lawmakers.
One of those Republicans, State Sen. Rob Schaaf, said he was "not going to defend (Greitens) if he's done the things alleged."
"If it's true," Schaaf said, "he ought to do the right thing."
In the Missouri House, Republicans were feeling "the full gamut of emotion," said a statehouse source. "Some want to dig in, (Greitens) has a few defenders. There are people who are ready to see him go today. And everything in between."
Any discussion by lawmakers of the governor's future will likely be on pause until Tuesday, when the legislature will resume its work in Jefferson City. Leaders decided to cut short Thursday's session as portions of the state braced for hazardous icy conditions.
Meanwhile, Greitens remained hunkered down, hoping his own squall would pass — although some Missouri Republicans doubted it would.
"I don't see how he can weather this political storm," Schaaf said.