If the discussion was about the US taking in hundreds of thousands of Syrian refugees in a matter of months, like Germany, then the "it's not about terrorists, it's about mass immigration and a lack of integration" line of argument might make sense - it's basically what Tom is saying about Germany.

But seriously, the number I'm seeing is 10 000 for this year. Let's put that a bit in perspective:
- 1% of the total amount of legal immigrants entering each year
- half of the number of Iraqi refugees accepted in 2013, and about 15% of the total of refugees in that year
- about equal to the number of Syrians who gained legal resident status in 2012 and 2013 combined

If you look at the wider proposals, the amount of refugees accepted from all destinations combined would increase over three years from 70k to 100k per year - so from 7% to 10% of the total.