Complex sentence: The incumbent president, Barack Obama, is ineligible to be elected to a third term because of the term limits established by the Twenty-second Amendment to the United States Constitution which do not allow a president to be elected to more than two complete terms.
Split into simpler sentences: The incumbent president, Barack Obama, is ineligible to be elected to a third term. Term limits established by the Twenty-second Amendment to the United States Constitution do not allow a President to be elected to more than two complete terms.