Like Alexis de Tocqueville nearly 200 years ago, I believe American society thrives when people act out of an enlightened regard for themselves that constantly prompts them to assist each other. I remain optimistic that our nation can unify around policies that promote a system of mutual benefit for people from all walks of life.

As President Donald Trump nears 100 days in office, we are moving closer to that ideal in some respects, but not in others. But no president can - or should - be expected to solve every problem alone. To be successful, leaders in any field must listen to everyone,...