After 06:00 in CNN's April 19 18, 2024 MTG says GOP support is ‘growing’ to oust Speaker Johnson there are several quick clips of Democratic representatives suggesting they would not vote to vacate if it came to that.

One in particular caught my attention. Florida Democratic representative Jared Moskowitz said:

(If) Marjorie Taylor Greene, someone who wants states to secede from the union, brings up a motion to vacate, I will not support her doing that under any circumstance. Democrats don't even let her rename post offices. I'm not going to let her make a motion to vacate.

Question: Why don't Democrats let Representative Greene rename post offices, and how do they prevent her from doing so?