More than two weeks have passed since Speaker Nancy Pelosi scrapped her Sept. 30 deadline and delayed a House vote on the Senate-passed bipartisan infrastructure bill, because progressives wouldn’t provide sufficient votes.

Several members of the Congressional Progressive Caucus don’t want to pass the bipartisan bill — which is limited to physical infrastructure — before the wider-ranging Build Back Better bill is in hand. They fear that if Sens. Joe Manchin and Kyrsten Sinema get their bipartisan bill unconditionally, the moderate duo will have freed their hands to kill or gut Build Back Better.

But when Pelosi accepted postponement, she also set a new deadline of Oct. 31 for passing the bipartisan infrastructure bill. We are now 13 days away from that deadline, and no progress has been made toward satisfying the progressive demand of an agreement on the Build Back Better passage. So, are we headed for another delay? Or will Pelosi’s Oct. 31 deadline prove firmer than her Sept. 30 deadline?

Nothing can be said with certainty, but there are factors that may weaken progressive resistance at the end of the month.

First and foremost is the precarious state of the Highway Trust Fund, which is how the federal government financially supports highway and transit projects. The fund was due to expire at the end of September, and the bipartisan infrastructure bill re-authorizes it for five years. A lapse in the fund would not instantly throttle ongoing projects, but it would put their financial stability in doubt and inject uncertainty into state and local planning. Pelosi initially tried to use that fact to pressure House progressives to support the bipartisan bill last month. But once Senate Republicans signaled they would support an emergency measure to extend the life of the fund for 30 days, the deadline pressure vanished.

Pelosi’s new deadline to pass the bipartisan bill is directly tied to the new deadline to extend the Highway Trust Fund, a point she reiterated last week. But can’t Congress just pass another short-term extension, like the one they just did? Sure, but at least 10 Senate Republicans would have to agree to overcome a filibuster. According to CQ, the only reason Republicans agreed to the last extension was that no new spending was necessary to keep the trust fund afloat for 30 days, but after Oct. 31, “the Highway Trust fund would need another cash infusion to keep funding authorized programs.”

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Unless the trust fund’s cash flow surpasses expectations in the next few days, it may be flat broke by the end of the month. Senate Republicans could refuse to approve  fresh spending to bail the fund out, especially since their leader, Mitch McConnell, can accurately point out that Democrats have an alternate solution — House passage of the infrastructure bill that he and 18 other Senate Republicans have already supported.

Another new factor is the supply chain crisis. Last week, Biden sought to reassure Americans that his team is working with port operators and retailers to address bottlenecks that have been keeping goods off of store shelves. In doing so, Biden drew a connection between long-term supply chain needs to the stalled infrastructure bill, saying, “We need to improve our capacity to make things here in America while also moving finished products across the country and around the world” and noting the infrastructure bill invests “billions of dollars for ports, highways, rail systems that sorely need upgrading — and would bring products faster and more efficiently from the factories, to the store, to your house.”

Against a backdrop of supply chain hiccups, do Democrats want to further delay  their plans for port and freight rail improvements? Or risk a disruption in the Highway Trust Fund?

Also looming is the Nov. 2 gubernatorial election in Virginia. What had been a swing state has looked increasingly blue, one that Democrats expect to win. Democratic governors have run the state 16 out of the last 20 years. Both U.S. senators have been Democrats for the last 12 years. Democratic presidential candidates have won the state in the last four elections. Yet the Republican gubernatorial nominee, Glenn Youngkin, is running only a couple of points behind former Gov. Terry McAuliffe.

McAuliffe confided to supporters in a conference call that Biden’s low approval numbers were dragging down his campaign, and he has been publicly expressing frustration that the Democrats in Congress haven’t passed the bipartisan infrastructure bill. Moreover, Politico reports that “[i]f McAuliffe doesn’t pull out a win, some pessimistic Democrats privately predicted a ‘collapse’ on Capitol Hill.”

All of these factors could change the Democrats’ political calculations. Last month Biden visited the House and signaled his support for the progressives’ stance on delaying a vote on the bipartisan bill, seemingly accepting that the only way to get physical infrastructure is to link it to trillions in health care, education, paid family leave, housing and climate spending.

But by the end of this month, with an agreement on the larger bill nowhere in sight, with the prospect of a disruption of transportation funding, with the supply chain an ongoing concern, and with the possibility of a disorientating defeat in Virginia, Biden could return to the House and declare that the only way forward is to pass the bipartisan infrastructure bill now.

Granted, even a presidential exhortation might not be enough to win a House vote. If no Republicans cross the aisle, just four dissenting Democrats would be enough to stop the bill. And last month the Congressional Progressive Caucus chair, Pramila Jayapal, claimed around 60 members of her caucus would vote “nay.” But not every caucus member was on board.

Even a presidential exhortation might be enough to a win a House vote. If no Republicans cross the aisle, just four dissenting Democrats would be enough to stop the bill.

New York Times columnist Michelle Goldberg, in a column praising Jayapal’s hard-nosed approach, relayed that Rep. Steve Cohen is “anxious about what he described as his colleagues’ ‘brinkmanship.’ If the bipartisan infrastructure bill had come to the floor, he was planning to break with his caucus and vote in favor. ‘These bills are important,’ he told me, ‘but they’re not as important as keeping the presidency.’” Cohen’s position may not have been the majority sentiment in the Congressional Progressive Caucus last month, but sentiments can shift under changing circumstances.

Of course, the scenario I’ve laid out is not guaranteed to happen. Biden may well remain convinced that the risk of open warfare with his left flank, undermining party unity, is a bigger concern than all the other risk factors mentioned above. But those risk factors may help explain the actions of the most inscrutable figure in this legislative drama: Sen. Kyrsten Sinema.

Sinema has been in no rush to seal and deal on the Build Back Better package, and has reportedly said she won’t vote for it until the bipartisan infrastructure bill — also known by the namesakes of its principal authors, Sinema-Portman — passes the House first.

Might Sinema be slow-walking negotiations — allowing concerns to build over the Highway Trust Fund, the supply chain and the Virginia election — in order to force an Oct. 31 stand-alone vote on Sinema-Portman?

Bill Scher is a contributing editor to Politico Magazine, co-host of the Bloggingheads.tv show “The DMZ,” and host of the podcast “New Books in Politics.” He can be reached at contact@liberaloasis.com or follow him on Twitter @BillScher.

This article was republished with permission from Real Clear Politics.