Was curious what their objection was: https://www.savedowntownmenlo.org/
The city is required by the state to build certain amount of high-density, low-income housing near transit (in this case, Caltrain). The city is proposing using land already owned by them -- three parking lots next to a congested downtown strip.
FWIW, looks like the main objection might be losing those three parking lots than straight up NIMBY.