Recently watching some youtube videos of cars being stopped at Inland Border Patrol Checkpoints some Google research was done to see whether this act was legal or not. Here are a couple of things found.

“Border Patrol agents are granted authority to question the occupants of vehicles traveling through an established checkpoint based on U.S. vs. Martinez-Fuerte. That was a 1976 Supreme Court decision that said permanent or fixed checkpoints set up by the U.S. Border patrol on public highways leading to or away from the Mexican border are not a violation of the Fourth Amendment.

Congress also gave the Department of Homeland Security authority, through the Immigration and Nationality Act, to conduct searches within a “reasonable distance” of the border, which DHS defines as 100 miles.

Hines points out, however, that federal laws and regulations are subordinate to the Constitution.

So it seems you are within your rights not to answer the Border Patrol agent at an internal checkpoint (this doesn’t go for actual borders!), but the agents are also within their rights to ask you about your citizenship. At least for a while. After that, they’d need probable cause to detain you.”

http://www.texasobserver.org/border-patrol-takes-no-for-an-answer-at-internal-checkpoints/

Also “”Border Patrol agents at checkpoints have legal authority that agents do not have when patrolling areas away from the border. The United States Supreme Court ruled that Border Patrol agents may stop a vehicle at fixed checkpoints for brief questioning of its occupants even if there is no reason to believe that the particular vehicle contains illegal aliens. The Court further held that Border Patrol agents “have wide discretion” to refer motorists selectively to a secondary inspection area for additional brief questioning. In contrast, the Supreme Court held that Border Patrol agents on roving patrol may stop a vehicle only if they have reasonable suspicion that the vehicle contains aliens who may be illegally in the United States—a higher threshold for stopping and questioning motorists than at checkpoints. The constitutional threshold for searching a vehicle is the same, however, and must be supported by either consent or probable cause, whether in the context of a roving patrol or a checkpoint search.^“

http://en.wikipedia.org/wiki/United_States_Border_Patrol_interior_checkpoints

When the United States has a man in the Oval Office whose own US citizenship is questioned all this makes sense; or does it?  Whatyareckon?