Assistant editor and Opinions contributor

Senate Majority Leader Mitch McConnell, right, and President Obama. (Reuters/Larry Downing)

At the end of last week’s Republican debate, moderator Bret Baier questioned each of the candidates about their commitment to the Republican Party. Would Marco Rubio, Ted Cruz and John Kasich support Donald Trump if he was chosen as the GOP’s presidential nominee?

After the past few weeks of intense in-fighting in which Trump has been called a “con artist” and a threat to conservative principles a casual spectator would have expected an unequivocal “no” from at least one candidate. But, of course, that wasn’t the case. All said they would support the businessman and, instead, strongly denounced their Democratic counterparts.

The moment illustrates the widely discussed notion of political polarization, a growing disdain our two parties have for one another and the subsequent dysfunction from divided government. Members of the Republican Party have made clear that winning the White House back from our Democratic president is their highest priority, even if that means handing it over to a man they expressly detest.

Our political parties are more polarized today than they were in the decades after the Civil War, the result of decades of growing political divide. Bipartisanship is openly scorned by congressional leaders, and even the more moderate Senate Republicans have refused to consider a nomination by President Obama to fill the Supreme Court vacancy, suggesting that a growing part of the party is unwilling to negotiate with the president on any level.

Democrats, on the other hand, have also rejected cooperation. Obama has routinely made it clear that he would use whatever power he has to work around or override Republicans in Congress. He has threatened vetoes outright in his State of the Union addresses and his chief of staff, Denis McDonough, assured reporters this year that “audacious” executive action would continue throughout the election year.

There’s no sugarcoating it. No one gets along. And this polarization is not just a Washington phenomenon. Polling suggests a sustained decline in centrism among the general public. Both conservative and liberal voters see their opposing party with greater animosity than in the past two decades, and as a result, liberal Republicans and so-called “Blue Dog” conservative Democrats have become a dying breed.

Political polarization has become so entrenched that some commentators are beginning to predict doomsday scenarios for the U.S. political system. Under this narrative, polarized politics stem from flaws in our Constitution and are the norm of U.S. history, and over the past few decades we have been exiting an unnaturally civil period of post-World War bipartisanship. Eventually, these pundits say, polarization will continue to rebound and increase to the degree that the federal government won’t be able to sustain itself or deal with national emergencies. Thinking back to the government shutdown in 2013 and multiple threats to repeat it, such a scenario doesn’t seem out of the realm of possibility.

These predictions are somewhat extreme, but at the same time, there doesn’t seem to be a quick-and-easy solution on hand. That’s because consensus among political scientists studying polarization is as rare as consensus among politicians. There is little agreement as to what is causing the trend. Some academics blame electoral policies, such as gerrymandering or an emphasis on the primary system, that have resulted in a mismatch between the more moderate general public and extreme political representatives. Others suggest that the problem is a deeper trend, reflecting the complicated political movements that have occurred in the past half-century. And still others have blamed a long list of other factors, from media coverage to genetic selection to women taking a greater role in populist movements.

But there’s one thing most experts agree on: Polarization at this heightened level is a problem. That’s because, in addition to halting crucial legislative initiatives and making it difficult to fill key government appointments, it hurts the economy by leading to more regular federal crises, such as debt ceiling impasses or the “fiscal cliff.”

The stakes are high and warrant an energetic debate. Is polarization a design flaw of our presidential system? What would be necessary to curtail our legislative dysfunction, and from where does it stem? What does the future hold for our two-party system?

Over the next few days, we’ll hear from:

David Broockman,  political economy professor at Stanford University;

Thomas Mann and Norman Ornstein, authors and scholars at the Brookings Institution and American Enterprise Institute, respectively;

Dana Nelson, author and professor of English at Vanderbilt University;

Jim Marshall (D-GA), former congressman;

Tom Petri (R-WI), former congressman;

Alan Abramowitz, political science professor at Emory University;

Jane Mansbridge, political science professor at Harvard Kennedy School.