Lofgren’s bill would impose site-blocking requirements on broadband providers with at least 100,000 subscribers and providers of public domain name resolution services with annual revenue of over $100 million. The bill has exemptions for VPN services and “similar services that encrypt and route user traffic through intermediary servers”; DNS providers that offer service “exclusively through encrypted DNS protocols”; and operators of premises that provide Internet access, like coffee shops, bookstores, airlines, and universities.
Invest in VPN providers.
If they are not blocking the access to the WHO.is servers you can get the IP address of the site and add it to your local hosts file.
Just use a VPN service at that point. VPNs also have the upside of your ISP not being able to see you visiting piracy websites.
Doesn’t the IP address change anyway?
Some do and some don’t. Even if the IP changes, the actual IP address will be shown on the WHOIS site. Alternatively, I am sure that the actual IP address of these sites is shared by non-American users on forums and other sites.