"This country must not miss this opportunity," McConnell said last week about tax reform - but this week, he must take the first step on the 'budget resolution,' which sets an outline for spending in 2018.
The plan approved earlier this month by the Senate Budget Committee would balance the budget within ten years - but, it would also allow the tax plan to create $1.5 trillion in new debt, meaning there would not be a balanced budget during that time.
That has left some Republicans voicing their concerns - and as we saw with health care, it doesn't take too many GOP Senators going against the President to derail any Trump plan.
It's also the first time that Senators have been back at the Capitol since the Twitter spat between the President and Sen. Bob Corker (R-TN), who has decided not to run for re-election in 2018.
Corker has also said while he backs tax reform, he doesn't want to see any tax plan create even a penny of new debt.
Meanwhile, we wait for the details of the GOP tax reform plan - not expected until November.