Complex sentence: Robertson was elected by the 2nd District of Oklahoma as a Republican Representative to the 67th Congress, defeating the incumbent William Hastings, making her the first woman to defeat an incumbent representative in a general election.
Split into simpler sentences: Robertson was elected by the 2nd District of Oklahoma as a Republican Representative to the 67th Congress, defeating the incumbent William Hastings. She was the first woman to defeat an incumbent representative in a general election.