Not Voting: 1 (Dem)
Keep in mind that an overwhelming majority of the American people are against the bill, in its present form. I suspect there are a litany of reasons this is so. But in a nutshell, there were just too many loopholes.
One of the larger sticking points was/is: the American people do not trust the government to close the border and enforce the provisions included in the bill, for proper enforcement in the future. And why should they? Government is not a trustworthy institution. This can easily be concluded by looking at Congress's low approval ratings.