Thom Tillis was once driven by a blazing ambition. Determined to become a political star, he rocketed from the Cornelius Town Council to the U.S. Senate in barely a decade.

The decision by Sen. Thom Tillis (R-N.C.) to not seek reelection next year could give Republican leaders headaches as he looks forward to wielding his newfound political freedom. Tillis announced ...

David Gergen served as a presidential adviser to four presidents of both parties and was a longtime CNN political analyst.