They cling to power and create monumental debt at the expense of the young and now shut society to save their sorry souls. And look at their "leaders," from Clinton, thru Bush II, Obama (he's always been a wanna be 60's radical), Trump, Pelosi, Schumer, McConnel,etc. They are an argument against Darwinism.
One of the reasons a representative republic may be better than a pure republic
Link: https://www.goodreads.com/quotes/108530-a-democracy-cannot-exist-as-a-permanent-form-of-government
And then the Dems will begin to fracture among long their very diverse group tectonic lines. You cannot reconcile AOC and Bernie with Wall Street and Silicon Valley... and the South side of Chicago.