The political divide between Democrats and Republicans is the worst it has ever been, according to a new Michigan State University report.

In the report, Zachary Neal, associate professor of psychology and global urban studies, applies a stochastic Degree Sequence Model to data on bill co-sponsorship in both the US House of Representatives and US Senate, from 1973 (93rd session) to 2016 (114th session) of political relationships among legislators, which uncovers a startling trend in congressional polarization to be the most divided in five decades.

"What I’ve found is that polarization has been steadily getting worse since the early 1970s," he said. "Today, we’ve hit the ceiling on polarization. At these levels, it will be difficult to make any progress on social or economic policies."

US House 96th Session (1979/1980) - shows weak polarization among Democrats and Republicans

US House 114th Session (2015/2016) - shows extreme polarization among Democrats and Republicans

Published last week in the journal Social Networks, the study found although thousands of bills are introduced each year, the average representative or senator co-sponsors only about 200. And when they decide with whom to co-sponsor bills, they view nearly half of their colleagues as “the opposition," said MSU Today.

While it is hard to think incivility among Democrats and Republicans today could get worse, it likely will, Neal said.

Increasing polarization among Democrats and Republicans have been in a 45-year bull run.

Polarization has created political turmoil in Washington:

Neal said the Patient Protection and Affordable Care Act of 2010 is a prime example. The Democrats held a narrow majority and passed the bill. Then seven years later when Republicans took control with a slim majority, they tried to repeal it.

"We’re seeing lots of animosity in politics," he said. "Although bills do occasionally get passed, they don’t stick around long enough, or never get fully implemented, and therefore don’t have lasting impact. This kind of partisanship means that our democracy has reached a kind of stalemate."

The solution to this dangerous polarization: elect more centrists to Congress, Neal added. But that will be extremely tough today because American voters are leaning towards nationalism, who are increasingly polarized too.

"This study raises new questions about the future of Congressional politics," he said. "In truth, the only thing that is bi-partisan in Congress is the trend toward greater polarization."

The political divide in America did not happen overnight. The trends at play took many decades to unfold, but now, it is only being realized.

Today's extreme polarization could be part of the Strauss–Howe generational theory, also known as the Fourth Turning theory, which could give way to a new era of politics once the political deadlock is over. Perhaps, maybe, that is a key indication the swamp draining is on the horizon. Turmoil is coming. Strap in.