We’ve often observed an odd quirk in the behavior of political partisans; they tend to exaggerate even when they could make their point without doing so.
The most recent example is the weekend protest in Washington, D.C., at which a very large number of people turned out to criticize the Obama administration. Fox News reported that "tens of thousands" turned out, as did all major news outlets. The Washington, D.C., Fire Department put the number between 60,000 and 70,000,