I doubt a Jewish Israeli computer scientist poses a threat. But posing a threat isn't the criterion. We don't just take anyone that isn't especially dangerous.
America is a nation and only those that further the aims of the existing nation should come. Even then it should be very few of those because America is already full.
We can't build enough space to live and infrastructure for the people that are already here. And our natural environment is already threatened by overdevelopment.
What do you mean "America is full?" Our population density is 182 of ~250 on a global scale. We have more space, money, and food per person than almost every other country on the planet.
The world is ridiculously overfull and Americans didn't make it that way. And the rest of the world is headed for rapid population increases to make it much worse. Americans shouldn't have to suffer for that; we've got a little space left and we should guard it jealously.
And just try driving in any major prosperous city at rush hour or riding the subway. Or renting an apartment in SF or NY. We can't expand housing or infrastructure in those cities and we're admitting millions of foreigners overfilling them even further.
America is a nation and only those that further the aims of the existing nation should come. Even then it should be very few of those because America is already full.
We can't build enough space to live and infrastructure for the people that are already here. And our natural environment is already threatened by overdevelopment.