Donald Trump

"We know about dictators in Latin America," Mexico's former president, Vicente Fox, tells NPR. "So I really want American citizens to really consider, is that really the best option that you have?"

Colorado Republicans meet Saturday to elect delegates for the Republican National Convention. Ted Cruz has been well-organized in the state.

Trump demands that Mexico pay up to $10 billion or risk the cutting off of wire transfers from the U.S. to Mexico and a cancellation of business and tourist visas for Mexican citizens.

Trump has gone on the attack against Wisconsin Gov. Scott Walker in his home state this week. But that could be a big political miscalculation heading into Tuesday's primary.

President Obama said Donald Trump's statements on nuclear issues show he "doesn't know much about foreign policy, or nuclear policy, or the Korean Peninsula, or the world generally."

In the first Republican debate last August, Donald Trump would not promise to support his party's eventual nominee. In September he signed a pledge to do so. Tuesday night, he reversed himself again.

The former presidential candidate has thrown his support behind Cruz ahead of the Wisconsin primary April 5.

Public figures face high bar to prove libel, and the GOP Presidential candidate will have to overcome decades of precedent to overturn law