A Maryland concert hall scheduled to open next summer is running into roadblocks from politicians who are not overly eager to take responsibility for covering cost overruns. Strathmore Hall, which was budgeted to cost $100 million and will become the second home of the Baltimore Symphony Orchestra, is supposed to draw the adjoining metropolitan areas of Baltimore and Washington, D.C. together in suburban Montgomery County, but so far, county and state officials can’t agree on who should be responsible for unforeseen costs at the site. The county has asked the state for an additional $3 million in assistance to finish the project, but state budget analysts say that they’ve already contributed more than $44 million, and the county needs to pick up the slack.