It does really appear that America's getting her own, homegrown oligarchs.

We've had them for a long time; basically the only time we've tried to reduce their power was the Great Depression and post-WWII era, but since the 70s we've been letting them off the leash.

Correct. 10/10 summary

Carnegie, Vanderbilt, Rockefeller... we've had them.

They've mostly kept a low profile since the Great Depression though. And plenty would be oligarchs were taxed out of the upper class by the WW2 tax brackets.

The families that lost their wealth in the Civil War and the families who had to pay a little more tax because of the New Deal and the people still mad about LBJ era civil rights legislation have all banded together.

America has had oligarchs for a very long time. The government is very much in the pocket of big businesses