Long-term Political Trends in the United States
In the past, people who are politically liberal have moved from rural areas to cities, and then from smaller cities to larger cities, or perhaps as people move from rural areas to cities to larger cities, people become more politically liberal. Since the House of Representatives is apportioned by population, and the Senate is apportioned with two senators per state, then polarization between the House of Representatives and Senate might occur. Economic opportunities exist for living in large cities, and millions of people who vote for Democrats live in states that often vote for Republicans at the state and federal level, and millions of people who vote for Republicans live in states that often vote for Democrats at the state and federal level. I am not suggesting changes, however, a possibility of polarization between the House of Representatives and Senate might occur.