O'Reilly thinks the total will not top 40,000 while Beck is said to believe it could be 300,000.
I'm with O'Reilly on this one.
it is notoriously difficult to estimate crowds, which is why the park police in Washington no longer do it.
So expect plenty of hyperbole on both sides as to actual numbers.
But 300,000, even with Sarah Palin speaking, sounds like a very long shot.
But I think Bill O'Reilly has probably got it about right.
Beck's problem is that his followers are almost all angry white men and women.
They are ordinary people who feel left out of the current political system and that their voices are not heard.
Beck has done a spectacular job of reaching them through Fox News.
But he has done so in part by demonizing other groups, Hispanics in particular on immigration issues.
Such tactics will make lots of people uncomfortable and will impose a cap on the numbers of people who wiil follow him.
His ratings have leveled off after spectacular growth which is telling in itself.
He lacks O'Reilly's ability to reach more into the mainstream.
Which is why I think his numbers will be no big deal today.
Time will tell.