For starters.
Article II, section one.
Before he enter on the Execution of his Office, he shall take the following Oath or Affirmation:--"I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my Ability, preserve, protect and defend the Constitution of the United States."
In June, he issued orders concerning the deportation of Illegal Immigrants which are contrary to existing law as passed by Congress. This is a failure of his oath of office. Nor is he anywhere granted the power to alter, change or ammend existing laws passed by Congress or issue orders equivelent to law.
After the BP Disaster, he put a moritorium on drilling in the gulf, but did not do the same in California or Alaska.
Article 1, Section 9
No Preference shall be given by any Regulation of Commerce or Revenue to the Ports of one State over those of another; nor shall Vessels bound to, or from, one State, be obliged to enter, clear, or pay Duties in another.
By placing limits on the issuing of permits to only the Gulf Cost and not all offshore drilling, he favored one state over another.
Others to follow, right now, I am off to the gun show.