who are the progressives?

I admit to laziness. I love asking for info here since it means not having to look it up myself and plus you all are usually a font of wisdom. So... here's something else I'm curious about.

If you had to name names, which politicians would you include as part of a Democratic "progressive caucus"? For example, I didn't know about Kucinich until he chose to run for president. Are there other politicians like this out there?

I'm curious about senators, congresscritters, governors, and mayors that might fall into this category (because I might have some chance of knowing or finding out who they are), but if you can't think of anyone at that level, just the existence of anyone like this at any level of govt would be interesting.