A few weeks ago, I speculated that chaos at American airports could be a pressure point that pushes lawmakers to end the partial government shutdown, and on Friday the Federal Aviation Administration has announced it was halting flights into New York's busy LaGuardia Airport due to a shortage of air traffic controllers. Flights into Newark Airport are also experiencing delays.

Air traffic controllers and security screeners are among those government employees who are being asked to work without pay during the shutdown, which is putting an increasing strain on them as it drags on.

So far, the problem has been largely manageable, but there are growing signs that it is about to become a much bigger issue, and on Thursday several airline executives issued warnings. JetBlue CEO Robin Hayes said, “We are close to a tipping point, as many of these employees are about to miss a second paycheck."

As I postulated a few weeks ago, right now both President Trump and House Speaker Nancy Pelosi, D-Calif., have political incentives to dig in to their positions over the border wall. Given that automatic spending and previous deals have meant that about 95 percent of the budget is funded, the effect of this particular shutdown has been limited and largely invisible to most people. But high-profile disruptions at major airports can change that dynamic quickly, putting more pressure on lawmakers to cut a deal.

LaGuardia in particular is a significant airport because it's a major hub for business travelers coming into New York, and also is where many of the shuttles between Washington, D.C., and New York come in through. If it becomes a choke point, it could lead to an outcry among people who have a lot of influence with politicians.