I, for one, want to see that same resolve applied to our own borders for the exact same reasons.While I would agree with your sentiment, President Bush has a lot on his plate. If he had lost Hispanic votes, President Kerry would be presiding over the Iraqi War and I don;t think that would be a pretty sight.
I do not believe he would have lost them. The legal hispanics immigrants and a large part of American citizens of hispanic descent support Bush and they support good immigration policy that strengthens our security and our society and would still have voted for him IMHO. Those who are left leaning and liberal would still have voted for Kerry.
So, I personally do not believe it would have cost him...but either way, we are now eight months past those elections and the issue still needs to be addressed with the same resolve we are displaying abroad.