Is Our Two-Party System Failing Us?

Our two-party system for the election of President and Vice-President has served us well for over 150 years. Although it makes it difficult for a third-party candidate to gain traction, it greatly reduces the likelihood of no candidate receiving a majority of the electoral college vote thus passing the election on to the House of Representatives. But most well intended schemes have unintended consequences, and one byproduct of the two-party system is an increasing polarization between those parties. 
 
 While there have always been clear lines separating the fundamental principles of the Democratic and Republican parties, it used to be the case that each party accommodated a wider range of political beliefs. But over the last 30 years or so there seems to have been a purification process taking place in each party that has skewed the range of political beliefs away from the center and toward the two extremes. Effectively each party has become more ideological in its political expression. This has largely hollowed out the center ground, leaving few moderates in either party. 
 
 Is this political polarization merely a reflection of what is happening in society? Much has been written about the way we socialize and identify with various groups today. While politics is certainly not the only factor in determining how we choose our friends and neighbors, it seems to be an increasingly important factor. Many people whose means are sufficient choose where they live, work, worship, and socialize based on basic beliefs that underlie their political philosophy. Social media allows people to easily share their opinions and beliefs across a wide network of peers who tend to aggregate based on similar beliefs. 
 
 It is likely identity politics has played a role in the polarization of our political parties. When an identity group aligns with a political party, it is usually because that party more closely represents the views important to the identity group. But the identity group also influences the positions taken by the party in ways that may tend to drive it toward an extreme. For example gun rights advocates have insisted on a narrow, literal interpretation of the Second Amendment and have made this a litmus test of support for any candidate for national office. This puts pressure on Republican candidates to adopt this position unless they are willing to risk running without the support of this constituency. Of course there are other polarizing issues such as abortion, LGBT rights, global warming, and capital punishment.
 
 There is a fundamental principle in nature known as regression to the mean. In simple terms it means that instances of extremes tend to be driven back gradually toward an average over time. It was first discovered in examples of inheritance, where certain exceptional traits of a parent generation were inherited by the offspring but to a lesser degree. For example tall parents tend to have children that are tall but not as tall as the parents on average. Conversely short parents tend to have children that are short but not as short as the parents on average. This process prevents a population from bifurcating into two separate groups representing extremes. 
 
 Sadly this process does not seem to apply to politics. In politics the guiding principle seems to be progression to the extremes. Is this a natural consequence of having only two parties; that over time the political philosophies of the parties tend to gravitate toward the extremes? Does this suggest it is time for a new political party that represents a more center based philosophy?