Perhaps Senate Republicans are smarter than they’ve looked in this infrastructure negotiation — or maybe they just lucked out. After the GOP’s negotiating group announced an agreement in principle on the bipartisan infrastructure bill, Chuck Schumer announced that he’d move forward on both that bill and the parallel $3.5 trillion package containing everything Republicans wouldn’t support. The bigger bill would move through reconciliation, cutting out the GOP entirely as long as Schumer can hold all 50 of his caucus together.

Not so fast, Kyrsten Sinema declared shortly afterward:

Sen. Kyrsten Sinema does not support Democrats’ $3.5 trillion budget plan that aims to deliver major components of President Joe Biden’s economic agenda that Democrats hope to pass after moving a separate bipartisan infrastructure deal that Sinema negotiated.

Sinema, D-Ariz., told The Arizona Republic on Wednesday she had reviewed the Senate Budget Committee’s spending framework and has told Senate leadership and Biden that she supports many of its goals, including job growth and American competitiveness.

“I have also made clear that while I will support beginning this process, I do not support a bill that costs $3.5 trillion — and in the coming months, I will work in good faith to develop this legislation with my colleagues and the administration to strengthen Arizona’s economy and help Arizona’s everyday families get ahead,” Sinema said in a written statement.

Sinema’s pledge to “support beginning this process” will still allow Schumer to open the reconciliation process. That means nothing, however, if Sinema votes against it. Or for that matter even if she doesn’t vote at all, since it takes a majority to pass a bill even under reconciliation. That means Schumer needs all 50 Senate Democrats plus Kamala Harris to succeed.

Does this mean Sinema opposes the reconciliation bill entirely? Suuuure doesn’t sound that way, as she wants to “develop this legislation” more to her taste, and perhaps more importantly, to bring it more into line with her purple-state constituency’s tastes. If this is the payoff to Republicans for cooperating on the bipartisan infrastructure package, it’s not exactly a vindication for the negotiators. It might shave a trillion or so off the final version, but Schumer and Nancy Pelosi will still get their massive hobby-horse bill.

Or will they? If Sinema’s getting worried about the ticket price in relation to purplish Arizona, Joe Manchin has to be getting the shakes in deep-red West Virginia. West Virginians have a long track record of being in the Bacon Party, so some of this might be mitigated by how much pork-barrel spending Manchin can direct to the Mountain State. However, with inflation burning a hole in working-class buying power and Democrats attempting an end run to get a lot of progressive wish-list items funded under the rubric of “infrastructure,” it remains to be seen just how enthusiastic Manchin will be for the Pelosi-Schumer Special.

For now, this looks like a mere speed bump for Schumer. Republicans better have another trick up their sleeves if they plan to play along on the bipartisan bill.