Top100 Songs that mention US presidents

Lost on the numbering, but Jefferson Airplane's "Mexico" and Paul Kantner/Jefferson Starship's "Mau Mau (Amerikon)" both reference Nixon directly.

Also, from the Hair soundtrack, "Happy Birthday Abe-y Baby."

xpost
Hmm... HSR version I'm familiar with dates from same period...

Well, the song is a bit too obscure for google to come to our rescue but the more I think about this, the more I think you're right. I'll give it to ya.

I don't know why I keep mulling this over, but now I'm sure you're correct.

Also: (if this counts) Happy Birthday Mr. President - Marilyn Monroe

Presidents on drugs:

Cypress Hill, "I Wanna Get High": "Tell Bill Clinton to go and inhale!"
My Dog Popper, "Acid Flashback" (Reagan suffers one!)
Country Joe & The Fish, "Super Bird" ("It's a bird, it's a plane, it's a man insane/It's my President, LBJ!"; and even HE drops some acid at song's end!)