We don't have to speculate, because it happened. Obama from 2007, meet Obama from 2014.
Back when he was campaigning for the White House, Barack Obama took aim at President George W. Bush's surveillance record. C-SPAN has the video, which can't be embedded, but read on for the transcript:
This administration also puts forward a false choice between the liberties we cherish and the security we provide.
I will provide our intelligence and law enforcement agencies with the tools they need to track and take out the terrorists without undermining our constitution and our freedom. That means no more illegal wiretapping of American citizens. No more National Security Letters to spy on citizens who are not suspected of a crime. No more tracking citizens who do nothing more than protest a misguided war. No more ignoring the law when it is inconvenient. That is not who we are. That is not what is necessary to defeat the terrorists.
The FISA court works. The separation of powers works. Our constitution works. We will again set an example for the world that the law is not subject to the whims of stubborn rulers and that justice is not arbitrary. This administration acts like violating civil liberties is the way to enhance our security. It is not. There are no shortcuts to protecting America.
Today, Obama might plausibly deny doing most of those specific things. But from his actions and tone as president, it's clear he's rethought some of his earlier positions and doubled down on others, such as the idea that the FISA court is an effective check on the NSA.