Basically, the Republicans want to take money from the stimulus package
Biden passed when he first came into office, and use it on infrastructure.
This would mean that Biden would take $700 billion from wildly popular
projects in that package and use it for something else, making him look
like a liar to the people and small businesses which are benefitting from
that law.
The Republicans agreed to only slightly more than $200 billion in new
spending, which would all be paid for by increasing the gas tax that
everyone, including and especially, the poor pays. The Republicans would
then be able to claim that the Stimulus package was nothing, since they
gutted it, and then they would be able claim that Biden raised taxes on
the people by alluding to the new gas tax. Biden called their bullshit on it
by saying he wanted $1 billion in NEW spending, not the $200+ billion the
mofos were proposing. The GOP will reject his proposal since it does not
involve punishing the poor and protecting the rich, and it includes real
new money for his agenda.
Biden will then be able to go back to the Senate and pass his infrastructure
bill without Republican support, using reconciliation.
This is equally about putting Joe Mancin and Kristen Sinema on the spot.
Once the Republicans reject Biden's proposal, then Mancin will not be able
to filibuster on their behalf. However, that snivelling snake is already working
on a proposal with Mitt Romney, that will effectively water down what the
people really need.