This is what I was driving at when I talked about the average age of the Senate. The people who have been in office for decades are (generally; there’s always exceptions) from a more conservative time in American politics, and they’ve been slow to embrace the shift in ideology within their base. I don’t want to vote out old people just because they’re old. If Ginsburg manages to make it to 100, I’d be fine with her being on the Supreme Court because she’s demonstrably one of its most progressive voices. I don’t mind if Elizabeth Warren runs for re-election for the same reason. But I think that long-term incumbency (and by extension, age) can result in representatives who are out of step with the electorate, and get re-elected because that’s pretty much always what happens for incumbents. I don’t think it’s ageist to suggest that, in general, older people don’t share the same priorities or beliefs as younger ones, and right now the beliefs and priorities of older people are vastly over-represented in Congress.
If you look at progressive causes like Medicare for All, or Fight for 15, or Abolish ICE, or criminal justice reform, these things aren’t being spearheaded by people like Feinstein, Schumer, or Pelosi. Instead, we get patronizing talk-downs about how universal health care just isn’t realistic, or why raising the minimum wage to match its 70’s-era spending power is just too dangerous, or that free public college tuition is ludicrous (“How would we even pay for it?” they demand, as they shovel hundreds of billions of dollars into the Pentagon’s furnace). Hell, Clinton compared agitating for these kinds of progressive causes to demanding ponies. This shit is only impossible because people like them say it is.
(Speaking of criminal justice reform, that’s what I see Harris getting hit for the most, because she’s a former prosecutor and doesn’t come out looking terribly good on that particular issue as a result.)