Sad. America was built on immigration, any decrease is a negative to me.

Would you be happy or sad if after years of drastically reduced Immigration America's tech dominance is destroyed?

As a non-American, I would be delighted. No need to have some single, powerful, 10000-pound gorilla have dominance over tech.

That assumes that the sole reason America has tech dominance is because of international diversity. But we've always been tech dominant, and according to many people we're not even diverse.

There are certainly a couple of examples of international diversity, and refugee acceptance, among two of the largest tech companies ever. Steve Jobs is the son of a Syrian refugee. Likewise, Sergey Brin's family came to this country as a Russian refugee.

Considering the number of SV companies founded by immigrants, we would have to look to decades, not years, to see the effects of this policy.

If the policy is wrong, it will be far too late to fix it once the results are clear. Foreign founders would simply go back to their home countries (or more reasonable alternatives, like Canada or Germany), and work in startup clusters there.

In about 20 years, I predict the Silicon Valley will be regarded as a startup cluster in the way Harvard is for higher education: the most well-known and prestigious, but only one of many excellent and sufficient options for your needs.

Considering I am in contact with my distant relatives that my great-grandmother left behind in Italy, my answer to your question would be sad.

>Considering the number of SV companies founded by immigrants, we would have to look to decades, not years, to see the effects of this policy.

So, in other words it will be insignificant?

>If the policy is wrong, it will be far too late to fix it once the results are clear. Foreign founders would simply go back to their home countries (or more reasonable alternatives, like Canada or Germany), and work in startup clusters there.

And we'll lose the nth social site, Uber for X, or fad app?

A historic example: when the Romans' olive groves were burned down by invaders, the Roman Empire was good as gone. Olives were a major source of revenue for the empire and they only produce fruit after several years. That didn't destroy the empire immediately but they never recovered.

We won't lose the next Uber or Snapchat. We will lose the next Apple or Microsoft.