I agree with O'Reilly who said the other night that if Al Quaeda smuggles a dirty bomb through our southern border and sets it off in Washington, or New York, etc., that's when the President gets impeached. Unfortunately it would take something of that magnitude to do it.
Unfortunately Oaths do not mean much to politicians. Political expediency rules in Washington. Those with the guts to step up and take a stand, usually pay a steep political price. Most want to hold on to the power and principles get put on hold.