Clivie C. Haley Jr. has been a loyal Republican for decades, giving to party candidates and acting as precinct captain in the 1st Congressional District.
But this spring he wrote a check to Frank M. Kratovil Jr., the Democratic nominee in that district, after incumbent Rep. Wayne T. Gilchrest, Kennedyville Republican, lost in the primary to state Sen. Andrew P. Harris, Baltimore County Republican.
Mr. Haley, 80, had given $1,750 to Mr. Gilchrest since last year. In May, the Queenstown resident gave $500 to Mr. Kratovil.
“I just think Kratovil is much closer to what Wayne Gilchrest is,” he said.
Harris supporters downplay the importance of cross-party support for Mr. Kratovil, the Queen Anne’s County state’s attorney. They said there are Democrats giving to Mr. Harris and that many of Mr. Kratovil’s Republican backers are merely disgruntled Gilchrest campaign supporters.
“I tend to discount that group of people,” said Kathleen A. Boland, chairwoman of the Talbot County Republican Central Committee.
Democrats maintain a slight edge in registered voters in the district, but Republican candidates have routinely defeated their Democratic opponents over the past decade. It’s not clear exactly how many voters switched parties after the February primaries. The state’s election board did not return a call Friday asking whether the agency had a record.
Anthony P. Mazzaccaro, of Princess Anne, gave $250 to Mr. Gilchrest days before the primary, then gave $250 to Mr. Kratovil in May. Anne M. Kimberly, of Easton and a lifelong Republican, had given $6,900 to Mr. Gilchrest since 2007, including $3,600 on the day of the primary. In May, she gave Mr. Kratovil $1,000 and plans to have a fundraiser in October for him at her home.
“I like Kratovil very much,” said Mrs. Kimberly, 91. “I don’t like this guy Harris.”
Miss Boland said Eastern Shore voters are still “just getting to know Andy.” She is not worried that Republicans will vote in large numbers for Mr. Kratovil in November, adding that Mr. Gilchrest was “not in sync” with many on the shore.
“I think the voters on the Eastern Shore are by and large more conservative, and that’s whether they’re Democrats or Republicans,” she said.
Mr. Mazzaccaro, who calls himself a fiscal conservative and social liberal, said his opposition to Mr. Harris is based partly on the influx of cash Mr. Harris’ campaign received for the primary from the Club for Growth.
Since January 2007, the Club for Growth has directed $442,431 in donations to Mr. Harris’ campaign, according to the Center for Responsive Politics. It said the club also spent more than $530,000 on ads opposing Mr. Gilchrest and state Sen. E.J. Pipkin, Queen Anne’s Republican, who also ran in the 1st District Republican primary.
“I don’t like the idea of outside money coming in and literally buying the district,” said Mr. Mazzaccaro, who teaches environmental science at the University of Maryland Eastern Shore.
A Harris spokesman pointed out that the majority of the nominee’s contributions have come from Maryland.
The Club for Growth is a District-based political action committee that supports generally conservative positions such as lower taxes, less government spending, school vouchers and deregulation.
Some Gilchrest supporters cited ads sponsored by the group against Mr. Gilchrest as a reason for their switch to Mr. Kratovil. Mrs. Kimberly called the primary campaign ads “absolutely criminal.”