Complex sentence: An unsuccessful candidate in several Florida state legislature elections, he was an unsuccessful candidate for Democratic Party's nomination for President of the United States in the 2016 election, before becoming the Reform Party's nominee for Vice President of the United States.
Split into simpler sentences: An unsuccessful candidate in several Florida state legislature elections, he was an unsuccessful candidate for Democratic Party's nomination for President of the United States in the 2016 election. He became the Reform Party's nominee for Vice President of the United States.