The whole Watergate thing with Nixon was about phone calls, right?

Nah, it was about people not OFFICIALLY (but almost certainly actually) connected to Nixon's reelection campaign breaking into the DNC offices at the Watergate hotel in order to steal sensitive election information and plant surveillance equipment.

Even more than that, though, it was about Nixon and his administration's subsequent coverup, since it couldn't be proven that the burglar spies, some of whom were formerly known as plumbers were acting on his orders.

The phone call connection is that some/most of the evidence was from the recordings of White House phone calls Nixon himself had insisted on due to his own paranoia.