On the Eastern Shore, Republican Rep. Wayne T. Gilchrest faces a challenge from a pair of conservative state senators. In Prince George's County, Democratic Rep. Albert R. Wynn tries to fend off the progressive activist who nearly unseated him in 2006.
With Maryland just the second state to hold congressional primaries this year, the mirror-image races are drawing national attention.
"It's a good preview of possibly the breadth of anti-incumbent sentiment," said David Wasserman, the House editor of The Cook Political Report, a Washington-based newsletter for insiders and political junkies. "You have two races, one on either side of the aisle, that will say something about the mood of the country."
In a state where competition has been redistricted out of the general election, the votes tomorrow will likely put the finishing touches on Maryland's congressional delegation for 2009. The winners of the Republican primary in the conservative 1st Congressional District - where state Sens. Andy Harris and E.J. Pipkin are challenging Gilchrest - and the Democratic primary in the liberal 4th - where attorney and activist Donna Edwards is taking a second swing at Wynn - are expected to coast to victory in November.
The other six House members from Maryland - Democrats Elijah E. Cummings, Steny H. Hoyer, C.A. Dutch Ruppersberger, John Sarbanes and Chris Van Hollen and Republican Roscoe G. Bartlett - face no more than nominal opposition this year. Neither Sen. Benjamin L. Cardin nor Sen. Barbara A. Mikulski is up for re-election.
But Gilchrest and Wynn - veteran lawmakers now accused of having grown too moderate for the districts they represent - are facing the toughest challenges of their congressional careers.
"This race, the presidential race, is about change," said Ronald Walters, a political scientist at the University of Maryland. "That could carry over into the congressional races. It could have a strong influence in turning over the incumbents."
Harris certainly hopes so. One of the most conservative Republicans in Annapolis, the 51-year-old physician has cast his challenge as a struggle for the soul of the Republican Party.
This is "an incredibly important year for the Republican Party," he told a Baltimore County audience last week. "We got shellacked in 2006. We got shellacked for a very important reason. We forgot our Republican roots. We forgot the Republican roots" that gave Ronald Reagan his landslide re-election in 1984.
