Photo: Sen. John McCain (cosmetic enhancements by Alex Constantine and EsteeLauder)

How could you forget Senator John McCain's "complete the danged fence" ad?

"It'll work this time," assures underwear model/Pinal County Sheriff Paul Babeu.

Well, today, while McCain took a tour of the border, he watched a woman climb over an 18-foot border fence in Nogales.

This gem of irony was among the updates of McCain's trip, posted on Twitter by his staff.

The first tweet puts McCain in Tucson with Senators Jeff Flake, Chuck Schumer, and Michael Bennet "headed south to Nogales shortly."

John McCain        @SenJohnMcCain

Just witnessed a woman successfully climb an 18-ft bollard fence a few yards from us in

John McCain        @SenJohnMcCain

Border Patrol successfully apprehended her, but incident is another reminder that threats to our border security are real

6:53 PM - 27 Mar 13