I find objecting to a secure border a fascinating political position.

Here's one real world example. In Calgary, my nephew works as a roofer. A semi-skilled labourer. He routinely makes in excess of $30 per hour. 

In the US, this amount of pay for this type of work is unheard of. Why? Laborers, by the millions, pouring across the border willing to work for $5 an hour. Sure, they may not work on Federal Government contracts, but they have the residential and minor commercial market covered. 

Can you blame the American workers for wanting to stop the flood of workers competing for their jobs in a manner that that can't compete against?

I sure don't.