A couple additions for consideration that comes from 15 years spent primarily as a Senior Committee staffer in the House and Senate:
At least 5 Republicans have signaled they would \*not\* have supported a vote in August for various reasons including stablecoin yield, the impact of the DeFi provisions on law enforcement, preemption of state law specifically with regard to prediction markets and a weak ethics provisions regarding the President. So this isn't just Dem opposition.
The Senate bill is drastically different than the House bill and also contains an entire additional crypto regulatory bill that was a product of the Agriculture committee which has jurisdiction over non-security derivatives. Even if the bill passes the Senate, the House might demand additional changes. Conference Committees that negotiate alignment on a bill like this can be a slow process. And that amended bill has to be passed by the House and Senate again. And even with no changes, another House vote is necessary to adopt whatever version the Senate passes.
The September legislative session also happens as general election campaigns are reaching peak activity and generally candidates don't want to see major legislation pass that might realign the priorities of outside groups they're raising money from.
From a traditional legislative analysis, it's honestly near-miraculous that a bill of this magnitude was being negotiated at all when Congress was so close to the August work period.