Complex sentence: Robinson later switched to the Republican Party, but the seat returned to the Democrats with the 1990 election, and no Republican held it until Tim Griffin won it again for the GOP in the 2010 midterm election.
Split into simpler sentences: Robinson later switched to the Republican Party, but the seat returned to the Democrats with the 1990 election. They kept it until Tim Griffin won it for the GOP in the 2010 midterm election.