Super Tuesday

Thirteen states vote Tuesday in presidential primaries or caucuses -- the most in 2016.

Donald Trump and Hillary Clinton lead in most other states, but with little polling, there could be surprises.

Super Tuesday is the biggest test yet for the presidential candiates. Here's the bar each will have to clear.

The stakes are high for the Vermont senator to perform well in early March caucus states.

But polling is sparse in several states, and Ted Cruz might get the biggest prize -- Texas.

The Republican candidates are back and ready to rumble.