Have you ever heard the story of the Indian and the snake?
There was this young indian brave that was out hunting high on a mountain alone. He stepped over a log only to be startled by a rattle snake. The snake was cold and probably going to die. As the brave examined the snake, the snake spoke to the young brave and said, "take me down the mountain where it's warm or I'll die". The brave was hesitant, knowing the danger, but the snake promised he wouldn't bite. So, out of compassion, the brave wrapped up the dieing snake in his shirt and hauled it down the mountain. When they reached the bottom, the snake was now warm and out of harm's way. As brave put the snake down and it bit him, fatally wounding him. As the brave lay there dieing, confused as to why, he asked the snake why he bit him. The snakes response, "you knew what I was when you picked me up".
Unless we can be sure that people aren't going to be dangerous to the people of the United States or our way of life, I believe we can't risk letting them in. If people from other countries are willing to play by the rules, meaning they have to assimilate to our way of life to a certain point, then they are welcome to come. I agree that we have a broken system and I believe that could be by design(different argument for a different thread). I believe in helping people but I'm not going to let a child molester stay at my house just because he's homeless(just an example). There's a lot of work to be done with our immigration regulations. Don't just let them in...bad idea...