Sparks flew when Sarah and Arlen rode the bus to a John McCain campaign rally in Delaware County, Pa. in September 2008. (William Thomas Cain/GETTY IMAGES)

But it’s not just about politics.

For example, in one steamy passage on page 156, he recalls riding on Sen. John McCain’s (R-Ariz.) campaign bus in 2008 with former Alaska governor Sarah Palin.

“She was a total charmer, very friendly,” Specter writes. “The few things she said were intelligent.” He doesn’t mention what they were, maybe because he was distracted.

“We were sitting virtually knee to knee in the cramped bus,” he writes. ”She radiated sensuality. Her skirt rode above her knees — not exactly short, but close.”

The excitement builds. . .