We know the kind of damage that will be done and the lives that will be lost if Robert F. Kennedy Jr. is put in charge of our health care system because we've seen it in action. Kennedy has a well-documented history of opposing life-saving vaccines, and he has pledged to stop funding research for treatments and cures for deadly diseases.

Allies of President Donald Trump have been quick to threaten primary challengers for Republican senators who don't back Trump's Cabinet picks and legislative priorities.