Um, the above is the Sunday School version of U.S. politics.
In reality, the executive has a tremendous amount of discretion. Just look at the Obama admin unilaterally extending an Obamacare deadline that was set by Congress -- and which did not give the executive branch the ability to alter. Didn't matter.
It's true that Congress is also responsible for NSA domestic surveillance. But every branch of government has a duty to ensure their conduct is constitutional.
First, where is your evidence of this opinion, I provided links to two sources describing the modern state of Executive powers and you basically call me naive without specifically refuting my evidence or points.
Second, the ACA (AKA Obamacare) does not specify specific deadlines except when reports to congress must be made. I googled for the deadline extension you were referring too, there were many, so please be more specific. Here is the text of the bill to read it for yourself (http://www.govtrack.us/congress/bills/111/hr3590/text). In general it says the the secretary of HHS shall set deadlines as reasonable, and hence giving the Administration the power to change their own deadline.
Third, I generally base my opinion off of personal anecdote since I have a family member serving as an elected politician in an executive office. Their job requires them to execute laws very specifically, often requiring them to consult lawyers regularly (even though they are a lawyer!). Laws can be tricky, and while I am not knowledgeable of government law I would be willing to bet the President is basically required to use section 702 of FISA whenever he can in regards to terrorism. But then again, my personal anecdote is from a county position.
Finally, it isn't a question of constitutionality. Congress said it was legal, therefore it's legal until the supreme court (or a lesser court that doesn't get appealed) says it is unconstitutional. I agree that the law is unconstitutional, but the executive branch does not get the luxury to exercise their opinions on laws like that.
As you continue to explore this area, you'll find pretty quickly that your family member's experience as a local elected official doesn't have that much relevance to NSA surveillance. Other than that, you're mistaken but well-intentioned, and I encourage you to read up on this topic. I might suggest my articles about government and the law over the last 15 years or so as a starting point.
In reality, the executive has a tremendous amount of discretion. Just look at the Obama admin unilaterally extending an Obamacare deadline that was set by Congress -- and which did not give the executive branch the ability to alter. Didn't matter.
It's true that Congress is also responsible for NSA domestic surveillance. But every branch of government has a duty to ensure their conduct is constitutional.