The donation from poultry producer Mountaire, reported last week by the Wall Street Journal, has Maryland Democrats accusing Hogan of impropriety as he vies to become the first Republican governor reelected in the state since 1954.
Hogan's potential Democratic challengers are using the article to criticize him, even though the Wall Street Journal article focused on a loophole that has benefited candidates from both parties. It allows corporate donors to write large donations to governors associations, avoiding contribution limits and disclosure requirements that would be triggered by donations to candidates themselves.
Douglass Mayer, a spokesman for Hogan, said the governor was unaware of any interactions between Mountaire and the Republican Governors Association. Mayer also said the accusations of "quid pro quo" don't make sense.
"The governor had an established position over a year before he was elected. He took office, and he put in very tough regulations that represented a compromise between the environmental and agricultural communities," Mayer said. "It was a very big win and a major environmental accomplishment."
Mountaire did not respond to a request for comment.
The RGA reported $450,000 ad buys in the Maryland governor's race on Oct. 21 and Oct. 27 of 2014. It received $250,000 from Mountaire on Oct. 31, according to a filing with the Internal Revenue Service.
Jon Thompson, an RGA spokesman, said the group does not solicit or accept donations for specific races and noted that Mountaire — with operations in Maryland, Delaware, Arkansas and North Carolina — had been a consistent donor.
Companies like Mountaire are not directly responsible for the removal of manure, although they contract with farmers who are.
Hogan, a businessman who was little-known in Maryland before his gubernatorial run, relied on public financing for his campaign. Outside organizations, however, were free to spend on his behalf.
A small-government conservative, he had criticized his Democratic predecessor, Martin O'Malley, for what he saw as an overly punishing approach to environmental regulation.
That included O'Malley's attempts to crack down on runoff from chicken manure used as fertilizers on Eastern Shore farms, a leading cause of pollution in the Chesapeake Bay.
But Hogan won the support of environmentalists and Democratic legislators when he negotiated a revamped set of regulations during his first months in office. The plan phased in stricter restrictions over a number of years and allowed extensions for some farmers if major problems arise.
The Wall Street Journal article also focused on a health-care company regulated by New Hampshire that donated to the Democratic Governors Association, which in turn supported then-New Hampshire Democratic Gov. Maggie Hassan's reelection bid.
But in Maryland, with just under six months until the Democratic primary, candidates competing for the chance to challenge Hogan in November seized on the Mountaire donation as a way of questioning Hogan's motivations.
"Larry Hogan should have the courage to tell the RGA he doesn't want their support in 2018 if it means taking money from corporate interests attempting to put profits over people," said Ben Jealous, the former president of the NAACP and favorite of some progressive groups. "Marylanders are tired of pay-to-play politics, and we will never have the change we need with a governor who was willing to sell us out on his very first day in office."
State Sen. Richard S. Madaleno Jr. (D-Montgomery), who is also running for governor, said, "Since his very first day in office, Governor Hogan has outsourced leadership to corporate interests who bankrolled his campaign."
The state Democratic Party, which has tried repeatedly — with limited success — to tie Hogan to President Trump, also weighed in.
"This is typical Hogan, who time and again has shown that he will always stand with his wealthy Republican donors over Maryland families," party spokesman Fabion Seaton said in a statement.