That's right. With mandates in place states say 10 more cases per 100K population. Here's the breakdown by state. Many states have had days with mandates (blue) and without (orange)

Drawn your own conclusions.
2/ pic.twitter.com/I2XknhFOQk

— Justin Hart (@justin_hart) December 20, 2020

Another objection: "Well, we can never know for certain HOW MUCH WORSE it could have been without masks." First, that's not science – that's unfalsifiable nonsense.
Maybe consider that the virus is beyond your control. See these 6 states with different mandates. Up and down.
4/ pic.twitter.com/HT7Ne9z5o4

— Justin Hart (@justin_hart) December 20, 2020

We also have numerous articles and studies demonstrating that mask mandates are not justified and that recent items cited by the CDC do not present strong evidence at all for mask mandates.
6/https://t.co/o1pE0Z5zP0https://t.co/readhMDcUL

— Justin Hart (@justin_hart) December 20, 2020

More from Ian. https://t.co/NhV3eMTJQn

— Justin Hart (@justin_hart) December 20, 2020

Spain's serologic survey shows those ALWAYS using masks got infected 25% MORE, than those never using it.

3.8% of the full accomplishing mask users and 3.9% of the partial users were infected Vs 3% of those never using it.

Official Spanish data, published but OC never aired. pic.twitter.com/4bSbpdqqlq

— plaforscience (@plaforscience) December 21, 2020

Justin asked if I could add these. Apparently the research was extensive to Florida as well. Here is some additional work done by the RG folks. pic.twitter.com/AKb2W6HkE8

— Kyle Lamb (@kylamb8) December 20, 2020

In effect, the masks are a viral trampoline making the virus exponentially more infective and reaching deeper into more thrombotic tissue.

Some evidence Kanas jumped on this trampoline in the summer. https://t.co/i3CvCXvRRz

— Kevin McKernan (@Kevin_McKernan) December 15, 2020