I just seen this. Without a doubt it is partisanship. I like the word polarization better although one leads to the other or polarization is caused by extreme partisanship. For most of my life I looked upon the two major parties as both wanting America to be safe, to prosper, to succeed. But each party had a different path to accomplish those goals. Yet, both parties did recognize the fact the other was out to make America successful, although the means differed.
I think that has been lost today. I no longer believe either party wants America to succeed, to prosper, to be that shinning city on the hill. I think both parties are only looking out for the good of their party, not the nation. If it weren't just for the good of the party, both would sit down together and work together at solving our problems, at making this nation the best possible nation in the world. But each party has discovered by not solving our problems, they have an election issue for the next election, one to fire up their base. Problems like healthcare, immigration, gun control, you name it are more valuable to each party as election issues than solving them. All in the search for votes. What the heck happened?