>> no, they're not interested. >> reporter: for much of the country, a patchwork of rules. just 18 states now require masks, at least for businesses. a new model from the university of washington suggests that some 33,000 lives could be saved by october 1st if nearly everyone wears a mask. with no statewide mask order in place, it's up to local leaders and just this afternoon, the city of miami passed an emergency order requiring masks in public at all times. if you don't wear one, you could face a fine up to $500. david? >> all right, victor oquendo again tonight. thank you, victor. meanwhile, president trump is traveling to another battleground tonight, as dozens of members of his own campaign staff are now in quarantine after his rally in tulsa. after tulsa, several staff members testing positive. and here's mary bruce. >> reporter: president trump in battleground wisconsin today, eager to turn the page from the coronavirus, even as cases are surging. >> we've done an incredible, historic job. >> reporter: but his rival, joe biden, today warning trump can't ignore the reality of this