WASHINGTON (AP) — President Joe Biden is wielding his weapon of last resort in the nation’s fight against COVID-19. Biden is promoting vaccination requirements across the country in an effort to force the roughly 67 million unvaccinated American adults to roll up their sleeves. It’s a tactic Biden never wanted to employ. But it’s one that Biden feels he has been forced into by a stubborn slice of the public. Biden on Thursday will deliver that message in Illinois, where he will visit a suburban Chicago construction site run by a company that’s imposing a new vaccinate-or-test requirement.