Complex sentence: In presidential elections, Williamsburg was a Republican-leaning city in the 1960s, 70s, and 80s until the 1990s when Democrat Bill Clinton won Williamsburg in both of his presidential campaigns.
Split into simpler sentences: In presidential elections, Williamsburg was a Republican-leaning city for most of the time from the 1950s through the 1980s. This changed in the 1990s when Democrat Bill Clinton won Williamsburg in both of his presidential campaigns.