I wish it were true, believe me, but I think that the word "massive" is a stretch regarding this march.
For starters, the video doesn't support that claim. The photographer walked WITH the pack for a while, so its size couldn't be determined. Then he actually jumped to the front of it - which tells us that the front wasn't very far away from him at any time. You want to make a march look large? Film it from the front and never let anyone see where the rear is.
Then there's the fact that I know that stretch of road quite well. The White House is cordoned off in such a way that really large marches CAN'T go past it. They'd bottle up. The road in front of the White House is narrow... only about 100 feet wide...
Larger protests typically go up Constitution Avenue... from close to the Washington Monument all the way to the Capitol. The White House isn't on that route.
I participated in what WAS a "massive" Ron Paul march a few years ago. It was big enough that the people in the middle didn't even know where the front or the back were. (The folks at the start were long finished by the time the rear even began.) Believe me... no coordinated chanting, as we heard in this video, was possible.
Ron Paul rallies are good things. But exaggering the size of one doesn't really hellp anything... or add to the movement's credibility.
BTW, one thing I *will* say that I haven't yet heard anywhere else is that the level of enthusiasm supporters have for Ron Paul remains at an extraordinary level - which (this is the part that's original) I think probably means that the movement is still rapidly growing.
The usual lifecycle of movements tends to be:
Enthusiasm/Rapid growth -> Complacency/Flattened growth -> Disappointment/Loss of support.
Based on that, the Ron Paul movement is probably STILL growing at an amazing rate. My fingers are crossed.

Gold is $1,581/oz today. When it hits $2,000, it will be up 26.5%. Let's see how long that takes. - De 3/11/2013 - ANSWER: 7 Years, 5 Months