FILE - Republican advisor Boyd Marcus in Richmond, Va. The head of Virginia’s Republican Party asked the state’s attorney general to investigate Marcus’s appointment to the Virginia Alcoholic Beverage Control Board. (Steve Helber/AP)

The head of Virginia’s Republican Party asked the state’s attorney general on Thursday to investigate whether one of Gov. Terry McAuliffe’s political appointments amounted to payback for a campaign endorsement.

Pat Mullins, chairman of the Republican Party of Virginia, pressed Attorney General Mark Herring (D) to open an investigation into the Democratic governor’s nomination of Boyd Marcus to the state’s Alcoholic Beverage Control Board.

A longtime GOP political strategist and adviser to former Republican governors James S. Gilmore III and George Allen, Marcus made headlines in August when he backed McAuliffe and went to work for his campaign.

McAuliffe touted Marcus’s endorsement during the race as proof of his bipartisan appeal. But Republicans claimed the Democrat had bought Marcus’s backing — first with campaign consulting work that brought him a combined $140,000 from a Democratic political-action committee and the campaign itself; and then with the appointment to the ABC board, a plum post that pays more than $100,000 a year.

Democrats say Marcus is more than qualified for the position given his deep experience in Virginia government, including service as Gilmore’s chief of staff. But Republican legislators have vowed to block the nomination, which requires General Assembly approval.

Mullins’s letter represents the GOP’s latest effort to derail the appointment and paint McAuliffe as an unethical wheeler-dealer.

“The Governor of Virginia enjoys very broad authority to make appointments to state boards and commissions,” Herring spokesman Michael Kelly in an e-mail. “Our office is not aware of anything that would indicate the Governor has misused that authority, but we’ll review Mr. Mullins letter when we receive it.”

McAuliffe’s office did not respond to a request for comment.

“I write today to ask that you open an investigation into Governor Terry McAuliffe’s appointment of Boyd Marcus to the ABC Board,” Mullins wrote. “This appointment . . . [raises] the troubling possibility that Governor McAuliffe bought this endorsement in the form of this appointment, essentially selling a state office.”

Mullins’s letter also makes reference to a now-concluded state police inquiry into allegations that during the campaign, McAuliffe offered to keep an existing ABC board member in her position if she endorsed him.

Immediately after the election, a Virginia Beach prosecutor asked state police to look into claims that McAuliffe had offered to keep ABC Commissioner Sandra Canada in her job if she endorsed him. Canada has declined to comment, but Harvey Bryant, now the former commonwealth’s attorney of Virginia Beach, confirmed that he asked state police to dig into the matter. The inquiry resulted in no charges.

“During the course of the gubernatorial campaign, my office received a complaint and I asked the state police to conduct a review,” Bryant said. “And they conducted that review and came back and briefed me, and we jointly agreed that no investigation was warranted.”

Canada’s removal, along with that of Board Chairman J. Neal Insley, created a brief power vacuum that led to the dismissal of a criminal case brought by ABC agents.

“As I understand it, the Virginia State Police have already opened an investigation into reports that then-candidate McAuliffe told a member of the ABC Board that she could keep her job, provided that she endorsed him, as Boyd Marcus did,” Mullins wrote.

“She declined to do so. That person was allegedly later told to clean out her office the day before Governor McAuliffe took office, creating a serious problem for ABC agents charged with enforcing our laws. At least one court case has been dismissed due to the fact that the Board ceased to exist for a time due to the Governor’s haste to put his own people in place.”