Well, he said "think" and not have done.
I am not sure either party is a great supporter of science though clearly if the topic is around Climate Change, then it will be mostly the Republicans in this camp.
I am hoping there is some decent opposition in 2020 from the Democrats as well as a good challenger from the Republican side, though you would have to want to put yourself in an ugly fight. I don't fit well with either side though Democrats have managed things better.
I think we're beyond the point of considering whether you "fit well with either side". Many, many long-time high-ranking Republicans are abandoning the party in droves. The Democrats are a reasonable party built on ideology and facts, and Republicans are a ridiculous party built on single-mindedly benefiting rich donors and lying. It's just crazy, and there is no equivalence.
I don't see either party being very pure, certainly, Hillary was as tied to corporate and banking interest as just about any politician. While I am not aligned with Sanders ideologically, he seemed one of the few that you could believe where he was coming from. But I am not sure they are similar when it comes to ideology. Any idea who the likely top Democrats that will run in 2020?
Bernie was the first serious Presidential candidate to refuse to take any money from corporate donors, so I wouldn't say that Hillary an aberration. Bernie would have attacked Obama with the same criticism - and he would have been right. But only because Bernie was the first of his kind. Bernie pushed her a bit to the left, but it was Hillary that was the mouthpiece for the original iteration of Obamacare back in Bill Clinton's day. Obamacare was always a compromise, and without that compromise Bernie's hope for Medicare-for-all was never going to happen. Since those are probably the two cornerstones of each individual's political career, I see no reason to say that they represent different ideologies. One is just more pragmatic. The one that combs her hair, if you couldn't guess.
As for Presidential candidates...
There's the "If you want to beat the racists, give them a handsome young charismatic white man" push to nominate Beto O'Rourke
There's the "Let's nominate a younger, but still old, female Bernie, who has recently added as much baggage as Hillary had and can't win" dream of Elizabeth Warren
There's the "Only possible person older than Donald Trump who wants to be President" Joe Biden
There's the "Intimidatingly sharp and yet alternately charismatic woman-and-black-and-Asian" Kamala Harris
There's the "Mistaken for a never-held-a-job-soccer-mom who will make you cry with a smile on her face" Kirsten Gillibrand
There's the "Probably going to be VP" Amy Klobuchar
...and some others I don't want to see and Governors I don't know enough about. I'm all about Kamala or a governor, myself. Maybe I gave it away above. I like Gillibrand, and she's popular, but I think Kamala is a better fit against a bully like Trump.