That's a dangerous game.
On any reasonable reading, Sharia Law as actual law is already illegal via the Constitution.
If the target is quasi-law ("parallel courts" and such) then there is considerable danger that the anti-Sharia law will be written in a way that can be used by anti-religious zealots to target such things as religious regulation of marriage, management of religiously affiliated institutions and so on.
You don't need new laws to deal with Islamism, just enforcement of existing laws, and better policy.
Deport illegals, deny citizenship to people who don't embrace American values, prosecute funding of terrorist orgs, etc.
And subtly and not-so-subtly point Muslims in America towards actually embracing the "Jihad is an internal struggle" option.