Complex sentence: A member of the Democratic Party, Kaine was elected to the Senate in 2012 and is the presumptive nominee of the Democratic Party for Vice President of the United States in the 2016 election.
Split into simpler sentences: A member of the Democratic Party, Kaine was elected to the Senate in 2012. He is the presumptive nominee of the Democratic Party for Vice President of the United States in the 2016 election.