I agree with your guess that the Senate is his true goal, following in the footsteps of his famous grandfather. (By the way, Clay's father said nuts to that. He went into banking instead of politics, moved to Colorado, and married a famous artist (Clay's mother).
Edited to add: OK, one more, then I'll shut up. Clay gave his announcement in both English and Spanish. He is also fluent in Chinese and Arabic. Here is the Spanish version.