Maryland’s Eighth Congressional District, stretching from Prince George’s County to the northern tip of Montgomery County, has switched back and forth between the Republican and Democratic parties in recent decades, though Rep. Chris Van Hollen’s (D-Md.) has held the seat since 2003. But in this year’s election, it may well switch back — Van Hollen is facing a well-funded and powerful Republican contender. Murray Hill announced yesterday that it would be filing to run…