With Trump leading the polls, establishment Republicans have suggested that either Rubio or Cruz could stop him if the field was narrowed. Are they right?

While Trump remains the clear front-runner in the GOP primary, according to national polls, the big question is how or if this changes once the field winnows?

After the Paris and San Bernardino attacks, terrorism was top of mind for voters. But now voters say the economy is the most important issue.

What issues do Americans care most about today?

Who stands to topple Donald Trump once the field narrows?