Border security could mean something like the ability to stop mass invasions of tanks, soldiers, and artillery. Bush and company don't think we need that with Mexico and they're right.
Or border security could mean the ability to interdict the flow of contraband. Every administration since Moses has been trying to do that on the Mexican border and has had incomplete success.
Or border security could mean stopping gigantic numbers of foreign nationals from coming across and doing whatever they want to do without supervision or restraint. Every administration just hasn't seen the point and has wished we'd stop bothering them about that. Bush is as bad as any of them on that point, but more brazen.
Or border security could mean the ability to interdict small groups of foreign nationals who want to sneak across the border over land to avoid the scrutiny of law enforcement because they intend to carry out terrorist acts. To have very much of this kind of border security might not be practicable judging from the success of generations of efforts to keep smugglers from moving large quantities of contraband across the border.
We might have a right to border security, but it's not going to be easy. Nobody's ever done it before. There's a long history of political, ethnic, racial, and philosophical issues that tie up the federal government on the subject of Mexico. Those aren't going to go away, so I guess we'll never have the kind of bank vault border security that would be needed to stop Mohammed Dynamite from sneaking across the border.
At the moment, I'd be happy just to see a halt to the population migration from Central and South America.