Five things to watch at the DNC this week

Story highlights

San Antonio Mayor Julian Castro will give the keynote address

Possible 2016 contenders, many of them governors, will be on display

Former Florida Gov. Charlie Crist takes his shot at the GOP

Anticipation is high for former President Bill Clinton's Wednesday night address

Charlotte, North Carolina CNN  — 

Republicans got first serve in their convention last week. Can Democrats break serve, or will the presidential race go to a tiebreaker in November?

Here are five things to watch for at the Democratic National Convention:

1. New man on the big stage – Most Americans have never heard of the mayor of San Antonio. They will after Tuesday night when Julian Castro becomes the first Latino to give the keynote address at a Democratic convention. Past keynote speakers such as Bill Clinton and Barack Obama made it to the White House. Maybe that’s raising too many expectations for Castro, but his speech will be looked upon the same way.

2. 2016 contendersSen. Marco Rubio of Florida and vice presidential nominee Paul Ryan gave blockbuster speeches at the Republican convention in Tampa, Florida. New Jersey Gov. Chris Christie’s keynote address didn’t go over as well. All three could make bids for the GOP presidential nomination in 2016 if Mitt Romney doesn’t win in November. So which Democrats are waiting in the wings? Govs. Martin O’Malley of Maryland, Brian Schweitzer of Montana and John Hickenlooper of Colorado all have an opportunity in Charlotte.

3. Turncoats – Is Charlie Crist the Artur Davis of this convention? Davis, the former Democratic congressman from Alabama who seconded Obama’s nomination four years ago, had a high-profile speech at the Republican convention. Now it’s Crist’s turn. What will the former Republican governor of Florida, who could possibly run for his old office as a Democrat, say when he gets in front of the podium in Charlotte?

4. What will Bill Clinton say? There’s probably more anticipation, and questions, around the former president’s Wednesday prime-time address. Once former adversaries when Hillary Clinton was running against Obama, Bill Clinton has become one of Obama’s strongest advocates. But the big question is what will Clinton say when he nominates Obama for re-election Wednesday? Obama campaign officials said they haven’t seen Clinton’s speech yet, but they said they are “not worried” about what he’ll say.

5. The ticket – The traditional role of running mate is to be the attack dog. Will Vice President Joe Biden slam Romney as much as Ryan attacked Obama? And how much of what the president will say in his acceptance speech is a defense of his first term and how much is an outline of what he wants to do over the next four years?