Bashing is simply a political tool made more popular by modern media. Unfortunately it often lacks substance just as the president being bashed lacks substance (or abuses it...)
As far as "Cool" , it was cool to pick on Clinton and the Monica episode as demostrated by popular media both left and right, but to voice concerns over the violation of laws and the systematic repeal of constituional rights is a duty and isn't considered "cool" by my peers (most all right wing and republican). Pointing out certain truths and lies was not cool and I lost advancement opportunities in my career to do so, but it was my patriotic duty to educate people about the damage Bush is doing to our country. I feel by being vocal I am protecting YOUR freedom regardless of your political persuasion.
Telling lies to start a war to kill Americans is by definition treasonous behavior. Telling the truth no matter how painful can NEVER be treason regardless of the situation.
The majority of Americans voted against him, and though he usurped the constituion the first term, and split the vote the second term, it is the Congress that is equally at fault for allowing him Napoleanic powers without just cause.
But from an historical perspective, the news papers in the 1700's and 1800's bashed our presidents much worse than we do today.... Remember the Sedition Act of 1798? Because of the "bashing", Adams outlawed all criticism of the presidency. If left alone, America would soon have become a dictatorship. Lincoln for example was also very despised at the time.
There has been a dumbing down of dissent with the rare exception being the 10 years from 1965 to 1975 where true dissent was voiced.
Nobody bashed Stalin, Mao, or Castro however. This is vital to remember.