Denver teachers stayed out on strike for a second day Tuesday as union representatives and school district management resumed negotiations. In fact, by some reports, the number of striking teachers grew on Tuesday. Students at one high school walked out in support of their teachers, and Sens. Elizabeth Warren and Bernie Sanders both tweeted that they stand with the teachers.

Negotiations revolve around teacher pay low enough to drive many into second and third jobs or out of teaching altogether. Teachers are also seeking changes to a bonus structure they say leads to high teacher turnover at high-poverty schools, arguing that a better way to support disadvantaged students is by reducing class sizes and hiring more support staff.

A week before the Denver teachers went on strike, one of the finalists for National Teacher of the Year in 2016 offered important context for the past year’s wave of teacher strikes. Nate Bowling’s tweet thread traced where he and his three fellow finalists have gone professionally since 2016. One, Oklahoma’s Shawn Sheehan, is doing a policy fellowship in Washington, D.C., after an unsuccessful run for Oklahoma state Senate. A second, Daniel Jocz, was recently on strike in Los Angeles. Bowling himself was also on strike last fall, in Washington state. And the 2016 National Teacher of the Year, Jahana Hayes, is now in Congress. Bowling’s kicker:

Dear reader: What does it say about the state of US schools that half of us felt drawn to DC to do policy work and the two of us that remained in the classroom both went on strike this year?

It doesn’t say anything good, that’s for sure—and with Denver teachers on strike and Oakland teachers preparing to strike, the uprising for public education continues.