Here is a poll to brighten your day. Bill Cassidy leads Mary Landrieu by 16 points, according to a survey by Magellan Strategies.

The poll was taken for the Cassidy campaign, but the results don’t seem far-fetched. If you add Cassidy’s share of the vote on November 4 (41 percent) to the 14 percent share received by the other Republican in the race (Rob Maness), you get a landslide of almost the magntitude projected by Magellan.

Things usually don’t work out quite so simply, and we shouldn’t expect every vote for Maness to tranlate into a vote for Cassidy. On the other hand, post-election day momentum is with the Republicans. Approval of the GOP has increased, and approval of the Dems has cratered, in the aftermath of the election, as America rallies behind its electoral verdict. We saw the same kind of spike in Obama’s approval rating after America decided to re-elect him.

Moreover, a 16 point Cassidy win would be very much in line with Tom Cotton’s rout of Mark Pryor in neighboring Arkansas. That result surprsied nearly everyone. A comparable rout in Louisiana wouldn’t.

That said, I’m expecting a somewhat closer race. But clearly it’s going to take far more than a vote on the Keystone Pipeline to keep Mary Landrieu in the Senate.