The US House Judiciary Committee is holding a hearing Wed. July 23, Chaired by Bob Goodlatte. On "Sanctuary Cities: A Threat to Public Safety." Chair Goodlatte has come a long way from a somewhat equivocal view on immigration a few years ago and is now outspokenly against illegal immigration. Trey Gowdy who chairs a subcommittee, is also on that Committee. The important thing, now, is to help line up Democrat members on the side of stricter enforcement and against sanctuary policies. You can leave a (polite and respectful) comment for the Committee at 202-225-3951.
Here is the minority (Democrat) contact info:
B-351 Rayburn House Office Building
Washington, DC 20515
202-225-6906