Munson, seeking a sixth Senate term after 16 years as a delegate, conceded making two pro-tax votes, but said Shank wrongly characterized the third vote, which was to increase unemployment insurance.
Both times he voted for a tax increase, it was to prevent a more damaging outcome in his district, Munson said.
As Shank waits to commit, others have expressed interest in the 2B seat, which covers eastern parts of the county, including Boonsboro.
Based on what he's heard, Republican Neil Parrott has concluded Shank is done with 2B.
"We're moving forward as if Chris Shank isn't planning to run," said Parrott, who lives near Hagerstown.
Parrott hasn't filed, but has formed a campaign fundraising committee.
Two other potential candidates are thinking about their next move.
"I'm seriously considering running," Democrat Brien J. Poffenberger of Sharpsburg said.
Poffenberger, the president of the Hagerstown-Washington County Chamber of Commerce, only would say he's considering many factors.
W. Christopher Motz, the chairman of the Chamber's board, said he knows Poffenberger might run.
Chamber bylaws don't prohibit Poffenberger from serving as president while running for office, although the executive committee would discuss the best way to handle it, Motz said.
"We want to help promote good people to run for office," especially if they represent business interests, Motz said.
Republican Stuart Mullendore of Boonsboro also might run for the 2B seat.
"The possibility certainly does exist," he said Thursday.
Mullendore, Boonsboro's mayor from 1976 to 1980, said he probably will make up his mind shortly after Wednesday's Republican Club picnic.
As of Friday, only one person officially had filed to run for a county or state office in Washington County, according to the Maryland State Board of Elections' Web site. That was Republican Michael Hough, who filed Aug. 14 for the Subdistrict 3B seat now held by Del. Richard B. Weldon Jr., an independent who isn't running again.
July 6, 2010, is the deadline to file for the Sept. 14, 2010, primary.
In deciding when to file, it's important to gain allies first, but also to let voters know you're interested, Mullendore said.
"It's a timing issue when it comes to the general public," he said.
Parrott, a traffic engineer, has had his name in the news this year for organizing two Hagerstown TEA (Taxed Enough Already) Party protests.
He said he's listening to public concerns and turning to his steering committee for guidance before he decides to file. The committee includes John F. Barr, president of the Washington County Commissioners, and Marilee Kerns, chairwoman of the Washington County Republican Central Committee.
"If Chris decides not to run, there will be interest," Kerns said.
"What we would like to see is a person running for every office," said Pat Heck, chairwoman of the Washington County Democratic Central Committee.
Local Democrats and Republicans, plus other groups, are planning to work jointly on a program to help people run for office or serve on boards and commissions.
Like Parrott, Shank said he's talking to people and building coalitions before announcing his 2010 election plans.
In 1998, as a Washington County delegation aide, Shank angered then-Del. D. Bruce Poole by refusing for several months to say if he was running against Poole. Munson was among those who defended Shank, who later resigned as an aide, then defeated Poole.
On Friday, Shank accused Munson of being "co-opted by the liberal Democrats in voting for taxes and spending," a backslide from earlier, more conservative years in office.
Shank cited Munson's 2002 vote to raise a tax on cigarettes and 2008 vote to increase millionaires' income tax. Both votes were part of deals to protect the University System of Maryland at Hagerstown.
"What's he going to trade a vote for next?" Shank said..
Asked about his own record, Shank said, "I don't trade votes. I compromise ... My vote's not for sale."
Munson noted the millionaires' tax was enacted so a controversial computer services tax could be repealed. The computer services tax could have cost Washington County hundreds of jobs, he said.
"It's too early for a campaign ..." Munson said. "People are really tired of this bickering."