Because he is a nutcase for one.
Such the same was said about President Bush.
Are you suggesting Tom's popularity on FR is an aberration? I would venture if Tancredo coupled a tightened border security with reductions in federal expenditures and more focused spending habits, ergo taxes, better schools, prison crowding reductions, healthcare solidification, social security protection measures, you'd see his popularity among average voters flourish wildly, much to the chagrin of unethical businesses.
One reminder though, illegal aliens nor felon businesses vote. Individual citizens do.
Show us something that he said that that actually supports this claim...