My list:  

1.  Deport the convicted criminals again and again and again.  (I read the 9th Circuit Appeals--some of these people have been recycled 10-15 times).  And I don't care if they have fathered twenty children here in the US.  Deport and re-deport the murderers, sex offenders, and drug dealers.

2.  Make NATO nations provide both money and troops for any future military activity.  They have been doing tokenism while the US has been spending our people's lives and trillions of dollars.

3.  Get our troops out of Afghanistan, Iraq and Syria.  Let the Arabs and the Persians fight their own battles for control of the Middle East.