If enough states pass this, it will be an effective ban. With enough US states banning them, the rest of the country will be forced to follow or risk creating economic barriers that would affect their tax revenue with the states that banned them having the advantage of not requiring extra bureaucracy for inter-state and international commerce. In addition, when the people in the lefty states see that some states have banned them and nothing happened (the lack of these passports did not result in anything happening), they will also be against them and push to not have them in their states.

Aside from being a human rights violation, these passports can be demonstrated to be useless for the CCP virus as every vaccine is leaky (you will still get the CCP virus if you are exposed to it after getting any of the vaccines available, it's just supposed to be less severe). So you can't actually make an argument for vaccine passports with this virus' vaccines. Vaccine passports are supposed to prevent the spread of a virus and with a leaky vaccine, they will at best be useless and at worst actually increase the spread with more asymptomatic people going around spreading the virus when they might otherwise stay home to recover if they were not vaccinated.