Fair question.
1st Amendment -
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
The first five words are the key. The first amendment is a restriction on the power of Congress, not an instruction to the president. The good Senator, being a member of Congress, is restricted by this amendment, but, the President has no constitutional power or restriction in this matter. It would be good for the Senator to educate himself on his responsibility as well as that of the President.