The senate voted this morning to proceed to debate on a package of gun control measures, centered around expanding background checks and toughening penalties, by a 68-31 vote. Debate and amendment will (almost certainly) officially begin tomorrow, and last several weeks, as hundreds of amendments - in good faith and bad - will be submitted.

Here's the roll call on today's vote. Sixteen Republicans voted in favor, while only two Democrats - senators from red states Alaska and Arkansas who are facing reelection next year - voted against.

These votes are hardly suggestive of how wavering senators would hypothetically vote on a final package, however. So far only two Republican senators - Mark Kirk of Illinois and Pat Toomey of Pennsylvania - are in favor of eventually passing some sort of measure and sending it to the House. And several other red-state Democrats who voted "yes" today, like Mary Landrieu of Louisiana and Jon Tester of Montana, are no sure thing for the final package.

The big amendments to watch going forward will be one on the more streamlined Manchin-Toomey proposal announced just yesterday, as well as longshots on restoring the assault weapons ban and instituting a cap on gun magazine capacities.

As of this writing, the Second Amendment still exists, despite this measure moving forward.