The Democratic majority's support for a Republican speaker was a startling answer to the question of who would wield the House gavel, but one that raised still more questions on how power would be exercised in the closely divided chamber over the next two years. "It's inside baseball, but it's vitally important inside baseball," said Tim Potts, an activist and former legislative staffer who has campaigned for a more open process in Harrisburg lawmaking. Mr. O'Brien promised just that as he acknowledged his unexpected elevation.