Gretchen's Take: The devil is in the delegate details

They say the devil is in the details, and that is true when trying to figure out how the delegate system works. We just focused on delegates Marco Rubio won before bowing out of the race. He has 172.

However, the 17 delegates he won in Minnesota are bound to him only. In Oklahoma, his 12 will be free to vote for whomever they choose.

Here's where it gets really interesting.

The nine delegates Rubio picked up in Tennessee are bound to him through the first two ballots at the convention. In Nevada, Rubio’s entitled to hold onto his seven delegates throughout the convention - to free them to do what they wish -- or to release them proportionally to the remaining candidates. It’s all up to him.

In Alabama, Rubio’s one delegate is bound until he or she is formally released or until two-thirds of the state's delegates vote to release he or she.

Got it? And that's just looking at some of Rubio’s delegates.