We’ve long argued that the politics of the economy — for most voters at least — can be boiled down to a single number: the monthly unemployment rate.

Yes, economists will roll their eyes at this too-simple calculation — nerds! — that misses the real underpinnings of the relative strength (or weakness) of the American financial system.

But, for the average voter who doesn’t have the time (or the inclination) to dive too deeply into the numbers, the unemployment rate — or, more specifically, the trend line of the unemployment rate over time — is the key indication of whether things are getting better or worse with the economy.

And that’s why today’s November jobs report is such good news for President Obama

Since a picture (or a chart) is worth 1,000 words — and with apologies to our chart-loving colleague Ezra Klein — here’s a look at the unemployment trend line since President Obama took office. (Big thanks to Matt McDonald at Hamilton Place Strategies for putting this together for us.)

What’s clear from the chart is that there has been a (pretty) steady decline in the unemployment rate since this time last year.

Republicans have and will continue to argue that the lots of lots of people — more than 300,000 — have simply stopped looking for work, which makes the drop in the unemployment rate misleading.

True enough. But, for Obama to win re-election next year he desperately needs some evidence that the economy is starting to move in the right direction. For at least the next month, the chart above allows Obama to make just that case.