Because these bills attempt to change freedoms the United States Constitution guarantees, it's unlikely these laws would survive legal scrutiny. In order to amend the Constitution, Congress needs 2/3 of both Chambers to vote in favor of the amendment.
Effectively, these bills would do nothing if passed, or at least they would quickly be overturned in the courts. Why introduce them, then? Efforts like this send a message - an unwelcoming message - to immigrants and refugees in our country.
Newsflash: immigrants and refugees are not evil or scary. Perhaps you have a neighbor, a colleague, a fellow church/synagogue/mosque member who is an immigrant or refugee.. From Aroostook and Washington Counties down to southern Maine, immigrants and refugees are part of our communities. Let's not make our neighbors feel unwelcome. Sending an unwelcoming message to the tired, the poor, the huddled masses yearning to breathe free is just, well, not in line with American values.