State senators are paid $43,000 per year.
After running unopposed in 2006, Munson has an opponent in the Sept. 14 GOP primary -- Christopher B. Shank, who is finishing his third term as a delegate.
No Democrats are running.
Shank has criticized Munson for voting to support $1 million for a multicultural center for Casa de Maryland, an advocacy group for Latinos and immigrants.
Critics say the group helps illegal immigrants.
Munson has said his vote was a mistake. During a recent interview, he apologized, saying, "I pushed the wrong button and did not realize" until after the day's legislative session was over, too late to ask to change his vote.
Munson said Shank can be seen as supporting Casa de Maryland by voting for the capital budget, which had money for the group. Shank has said legislators can't be expected to support every last item in a budget, but Munson said Shank's vote is fair game.
Although Shank has painted him as soft on immigration, Munson said he's not.
Munson said he supports Arizona's strict new immigration law and cosponsored an "E-verify" bill forcing employers who get state money to verify that workers are in the country legally.
Shank was a House co-sponsor.
Munson said constituents' main concerns this year are jobs, taxes and illegal immigration.
Like Shank, Munson has signed a Taxpayer Protection Pledge to "oppose and vote against any and all efforts to increase taxes."
Munson said he's twice voted, reluctantly, for tax increases during his time in the Senate, both times to protect University System of Maryland at Hagerstown funding.
A higher income tax on millionaires had little effect on Washington County, he said.
Donald F. Munson
Date of birth: Dec. 21, 1937
Address: 117 W. Magnolia Ave., Hagerstown
Education: Bachelor's degree in mathematics from Johns Hopkins University in 1968
Occupation: State senator
Party affiliation: Republican
Political experience: State delegate from 1975 to 1991; state senator since 1991