I'm not sure that Congress.org is exactly Congress...
I didn't click on it but if it was legitimate it would be:
Congress.gov
No, but when you send a letter thru Congress.org, it goes to your congresscritter. Of those who send a letter to their congressman thru congress.org, it is currently 80% for border security and reducing immigration, and 20% for amnesty and increasing legal immigration. I have little doubt that it is probably pretty close to the same averages thru any such service. How effective it is, I cannot say, but I think if I were a congressman, I would take notice of the percentages, that is unless I had already pillaged and looted and been paid off enough that I was ready to get sent home.