Nixon was hated for decades before he became president, but not at this level.
One of the reasons GWB is so hated is because they lost the House in 94, and thought it was only a matter of time before they regained control. They think THEY belong in power, and can't deal with the thought that perhaps they don't.
Notice that the rhetoric and attacks have greatly increased ever since Alito was nominated and it was clear almost immediately that the 'Rats have no chance to stop him. The 'Rats have lost the House, the Senate and the White House; their last and most important bastion, the Courts, is now in danger of falling as well. They are DESPERATE to regain power, and would lose the WOT if necessary to get back in.
They hate GWB because he's kicked their sorry asses out of the seats of power. Sucks to be a 'Rat.