But back to those colossi, our most famous example is probably the giant bronze statue of the Roman goddess that stands in New York Harbor. We got it as a gift, of course, but still, it's ours now. Then there's the seated colossus of Lincoln at his memorial in DC, and the partial colossi of the four presidents carved into a mountain in South Dakota (which also gives an example of a fairly recent person being memorialized, as Teddy Roosevelt had been president less than 20 years before the project was started and had died less than 10 years before). There's another, much less well known mountain relief carving of three Confederate heroes in Georgia, begun shortly before the Mt. Rushmore project, by the same sculptor, but not finished until the early 70s. (The early 20th century seems to have been a good time for colossal sculpture in America.) So the MLK colossus is a bit unusual for us, since it's been a while since we've had one of these, but not without its precedents, and rather firmly in the tradition of honoring great men who have been dead for a while. (I'm going to leave aside the whole genre of colossal roadside monuments, which is nevertheless worth thinking about in this context. And who knew how many colossal religious statues there were world-wide? Holy Cow.)
So what about the MLK monument? Well, while we haven't been building a lot of serious colossi for recent leadership in the US, some other countries have, and they tend to be the kind of countries we invade or don't/didn't get along terribly well with. Most people probably remember the statue of Saddam Hussein that we helped pull down in Baghdad back in 2003, and more recently there's Gaddafi's colossal fist with American warplane. But there are several others, from our more traditional rivals.
For comparison, here's the MLK statue (which seems to be a bit redder in most photos I've seen):
He's emerging from the rock, a bit stern, with lots of sharp edges (check out the crease in his pants). Here's a better shot of his face (AP photo):
And the Immortal Statue of Kim Il Sung:
In the end, it's hard for me to look at the MLK statue and not think of these other ones. Maybe state-sponsored architecture is always going to have some of that uncomfortable aura of official propaganda, but I'm sure another genre would not have evoked the same awkward (to my mind anyway) comparisons. I haven't been there yet, so it might be that this is all moderated in the context of the Mall, with Lincoln sitting not far away. (BTW, MLK is slightly taller than Lincoln would be if he stood up, so they're more or less made to the same scale.) I'll keep you posted.
(I'm of course not the first one to comment on this. Here's a NYTimes article from 2008 and you can easily search for some blog entries here and there.)