By Tony Fratto, (202) 822-1205, tfratto@hamiltonps.com

View Jobs Day Cheat Sheet here.

Over the past several months, the HPS Jobs Model showed very little chance that the President would reach the political milestone of getting below 8 percent unemployment before Election Day. But today’s surprising drop in the unemployment rate, from 8.3 percent to 8.1 percent, suggests the President may in fact succeed.

As our HPS Jobs Model shows and others have observed, the driver of the fall in the unemployment rate over the past year is not so much jobs created, but instead people dropping out of the labor force. And this month’s jobs numbers are just one more example of the power of labor force participation in this metric.

This month, the household employment number fell 119,000, but 368,000 people dropped out of the labor force. By this measure, we lost jobs, but the unemployment rate fell due to shrinking labor force participation.

I’m sure the President would rather not get there this way, but it does prompt the question: How many people need to drop out of the labor force for the unemployment rate to dip below 8 percent by Election Day?

If zero net jobs are created, an average of 140,000 workers would have to leave the labor force for each of the next two months for the unemployment rate to drop below 8 percent. We just saw 368,000 people leave the labor in one month, so a 7.9 percent unemployment is certainly not out of the question.

However if the labor force participation rate holds, the President would now need to see 257,000 jobs per month for the unemployment rate to drop below 8 percent.

It’s certainly possible that the supply of labor falls enough that the unemployment rate actually gets below 8 percent before the Election, but it would be like sneaking into the party through the out door.

Tony Fratto is a Managing Partner at Hamilton Place Strategies, former Assistant Secretary at the U.S. Treasury Department, and a former White House official. He is also an on-air contributor for CNBC.