Super Tuesday

With the Iowa caucuses and first primaries just weeks away, many voters say they're still confused about how presidential candidates differ on health care. Here's a guide to key issues and terms.

The four remaining GOP presidential candidates faced off in Detroit on Thursday evening just as sniping in the party to try and stop Donald Trump has reached a fever pitch.

At many precincts in the 13 states that held party primary votes Tuesday, officials reported record voter participation.

Hillary Clinton and Donald Trump dominated in the South, according to Associated Press results. Bernie Sanders and Ted Cruz won their home states, and Marco Rubio gained his first victory of 2016.

Donald Trump and Hillary Clinton are expected to roll to victories in the South, leaving their rivals trying to scrape for wins elsewhere on the biggest voting day of the year so far.

In important Super Tuesday states with a high number of born-again voters, Ted Cruz is losing to Donald Trump, and Marco Rubio is eating into his support with evangelicals.

In stump speeches since his loss in South Carolina, Bernie Sanders has taken shots at Hillary Clinton and Donald Trump. He has also seemed to temper his talk of political revolution.

Donald Trump and Hillary Clinton are expected to up their delegate leads and pull away from their rivals. But those aren't the only things that could happen. Be ready for surprises.

In 2008, Clinton suffered a crushing defeat as black voters rushed to Barack Obama — the beginning of the end for her campaign. Now, a win in the state would give her momentum for Super Tuesday.