Because they don't know how to market. Hell they even got like 3 votes from the GOP on the bill...
The GOP is still using the same BS lies about it that have been around since my father was in college. (one day it is pot...THEN YOU ARE HOOKED ON HEROIN AND METH AND KILLING PEOPLE!!1!!!!!!!1111) Only Boomers buy that crap anymore and half of them are high anyways. Marijuana legalization not only makes the youths happy (distracting from the student loan problem that Biden is not dealing with) but it shores up the minority vote literally everywhere. The Middle, most of whom could give a rats azz if people get high, will support the tax money it brings in and the Far Left will love the decriminalization in general. hell South Dakota showed that even Red States are not as against this as the fundies hope...cause anyone that isnt a fuckwit that might be Right of Center wants less rules not more rules.
The only people who truly are upset are cops, cause finding a bag of weed on a Darkie is an easy way to find a new snitch. After a year though they won't care either because it makes their job a helluva lot easier. Then it will just be the Prison Industrial Complex that will care and well fuck them and their backwards opinions on how to rehabilitate.
This is a gimme putt, especially since it won't pass the Senate. (meaning it doesn't matter...yet!) Hell for a party that usually only goes by what they read in polls they are just being derelict here. Last year polling showed majorities support full legalization. They should make this a top line item, and when it fails they run the crap out of ads stating how the GOP is the party of big government over reach.
I don't know who the Dems having doing their strategy but they should be fired yesterday. To say they have dropped the ball since Biden took over is maybe the biggest understatement ever. COVID is waning, the economy is strong, unemployment is way down and jobs are way up. We havent gotten over-involved in The Flaccid One's Late Life Crisis and we are getting a supremely qualified Justice for the Court. (along with plenty of other openings left unfilled by the fuckwits) But no...they let the fucking talking points be about the border, gas prices and so on. From now until September The House should be putting forth an aggressive agenda. Pass every bill you can to show the voters what the Dem Party stands for and what the GOP loathes. (and Biden should be going town to town touting all of them!) They hate people having fun, they hate people being able to afford health care, they hate education, they hate infrastructure, they hate women having rights, they hate Blacks, they hate Jews, the really hate Muslims and they absolutely hate equality. They are anti-gay, anti-union and anti-democracy and they say so openly. So pass everything in the agenda, especially if the Senate will fail to pass it. Then from September to Election Day you run ads saying "You saw what we want, you saw who stood in our way. If you want these things vote or stop whining!" (use better words ;^) ) Put some pressure on...whatever it is they are actually doing is worse than prevent defense in a one score game.