There are many reasons not to allow them in.
First, IMO, I believe their standards far short of our safety requirements, but somehow they seem to skirt around those requirements and run on our highways.
Thus they create a public safety hazard on US soil and if any accidents take place on US soil it is the US taxpayer that pays the cost, in the latest case, hospital bills of illegals using our hospitals and emergency services.
Second, IMO, I believe by allowing their TRUCKS to run our highways it takes away freight from US truckers and that is unforgiveable of lawmakers to allow such an avoidable situation to take place.
Third, IMO, we have an 'OPEN DOORS' policy at our borders - weather it is by design, mistakes, stupidity, politics or whatever - it must end. Every day that we continue with our current border patrol policies we put Americans in danger. I don't care if it is the south borders, north borders, east or west - PROTECT OUR BORDERS and stop worrying so **** much about other countries borders and being politically correct on everything we say or do.
Political correctness is what screws us up everyday.