What he means is, as the president acts more and more lawless by disregarding the constitution and the separation of powers thereby building excessive power in the executive branch, he is making the constitution null and void. We are no longer a nation of laws according to professor Turley, instead we are a nation ruled by lawless men who are doing what they please and who are truly living above the law. (see 5:13min video)
One note that I will add. The professor's attempt to compare the former administration with the latter. He stated that Bush's administrative was guilt of the same practices as Obama. Simply not true! Bush had the full force of a biased left wing media railed against him. The media opposed Bush on everything he attempted most times unjustly.
In addition the Democrats were a true opposition Party unlike the feckless Mitch McConnell John Boehner Republicans in Congress today. Democrats attempted to undermine the Bush presidency at every opportunity.
Democrats lied on Bush about WMD, they lied about the war and attempted to sabotage America's war efforts repeatedly. Democrats fought President Bush's every endeavor. Republicans on the other hand as professor Turley pointed out stand inertly by watching the country being destroyed, watching the constitution being violated. It's as if Republicans have no soul, no love for this country so they stand by doing nothing.
The Professor's warning is that at some point, very soon if Obama and Democrats aren't stopped. This country will cease being what it was founded to be. Again the Professor is a Liberal. He states that he agrees with most of Obama's policies he disagrees with the unconstitutional and lawless ways in which Obama is institutionalizing the Left's agenda on Americans.
Americans should be outraged! Where is the outrage?