Phrases like "revisionist nonsense" and "it is silly to say" should likely be used sparingly unless you have a very deep grasp of your subject matter.
Conflating the Tonkin Gulf Resolution with America's war in Vietnam would be a mistake. In bringing Tonkin into an argument you may wish to acquaint yourself with records detailing the Johnson Administration's orchestration of the resolution. See Michael Beschloss's work for instance, or the Pentagon Papers, either portions of the full set or the single volume if your time is short. With Tonkin Johnson was reacting from fear of voters, but the documentary record shows clearly that the Administration wished to expand the war despite public sentiment, not because of it.
In arguing that the war in Vietnam was popular you will likely want to look at some actual polling data, http://www.gallup.com/poll/119... for instance. Anecdotal evidence such as Nixon's 1968 platform may also prove useful to you.