I'm hoping Manchin, or some other Dem, will kill the $3.5T in the Senate. I think Pelosi is putting this forward only because AOC is leading a shakedown, and Pelosi needs those votes to pass the $1.2T.
As for the $1.2T, we've been talking for years about our crumbling infrastructure. Trump campaigned on it - $2T, I think - pretty hard in 2016 so the idea WAS even more popular than the 19 Repubs that voted for it.