My first thought was: The Republican(*s) [Verb wave] [Noun heads] for Washington. (similar to waving hands for Detroit)
Next: The Republican [Noun wave] [Verb heads] for Washington. (similar to the Republican handshake)
And Finally: The Republican [Noun wave] [Verb heads] for Washington. (see 5.c. below)
1. To cause to move back and forth or up and down, either once or repeatedly: She waved a fan before her face.
2. a. To move or swing as in giving a signal: He waved his hand. Nouns
4. A movement up and down or back and forth: a wave of the hand.
5. c. A rising trend that involves large numbers of individuals: a wave of conservatism.
d. One of a succession of mass movements: the first wave of settlers.
Defintions from thefreedictionary.com
The two pictures of people waving on the page didn't help disambiguate the headline for me.