About a decade ago I attended an internal presentation at Microsoft, made by a person who was lobbying immigration changes on behalf of that company. He explained this phenomenon - in some parts of the country the voting public does not have the attention span to listen long enough to make the distinction between "immigrants" and "high-skill immigrants". For that reason many politicians who are privately supportive of high-skill immigration still prefer not to try the patience of the voters, and come out against all immigration in public. Especially when there is an opponent who is ready to yell "he's soft on immigrants!".
About a decade ago I attended an internal presentation at Microsoft, made by a person who was lobbying immigration changes on behalf of that company. He explained this phenomenon - in some parts of the country the voting public does not have the attention span to listen long enough to make the distinction between "immigrants" and "high-skill immigrants". For that reason many politicians who are privately supportive of high-skill immigration still prefer not to try the patience of the voters, and come out against all immigration in public. Especially when there is an opponent who is ready to yell "he's soft on immigrants!".