BS. How is that even remotely true, when the GOP is filled with the most corrupt, money-fueled politicians ever? If "failing to run purity tests" is what keeps a party out of power, then wouldn't logic dictate that the Republican party should rightfully be in its death throes?
Gerrymandering and voter suppression is how the GOP gained control. To ignore that is to ignore the struggles of very very large portions of the US population, mainly people of color, who overwhelmingly vote Democratic.
So then you're left with a bunch of pissed off white liberals who demand flawless messianic figures at every level of the government, because they don't realize how much of the country is being oppressed by the GOP. Purity demands of Hillary hurt her campaign, and the purity argument of having to "overthrow" the Democratic party "to weed out corruption" hurt downballots, because it cast the image that the entire party couldn't be trusted. Let's maybe not make the same mistakes moving forward in the future and not vilify someone like Cory Booker, who has a consistent ideology and already has a strong, loyal base.