Thanks to Woodward, Bernstein and Deep Throat, the first rule of investigative journalism is “Follow The Money.”

The rule works for Muckety, too, especially when it comes to politics. Connections between politicians and their donors are always revealing.

A case in point: A story by Michael Cooper and Leslie Wayne in Thursday’s New York Times. It focused on the wealthy Paul E. Singer, a hedge-fund founder and backer of Rudy Giuliani’s presidential bid.

Not every candidate would welcome an endorsement from a guy known as “Meathead.”

But when that guy is Rob Reiner — Meathead in the 1970s television hit All in the Family — you take the endorsement and run.

Reiner, the 62-year-old actor, director, comedian and political activist, and one of the most connected people in Hollywood and Democratic politics, came out for Hillary Rodham Clinton in September.