MARC THIESSEN: Explain the Chinese spy, Sen. Feinstein.

Imagine if it emerged that the Republican chairman of the House or Senate intelligence committee had a Russian spy working on their staff. Think it would cause a political firestorm? Well, this month we learned that Sen. Dianne Feinstein (D-Calif.) had a Chinese spy on her staff who worked for her for about 20 years, was listed as an “office director” on payroll records and served as her driver when she was in San Francisco, all while reporting to China’s Ministry of State Security through China’s San Francisco Consulate. The reaction of the mainstream media? Barely a peep.

Feinstein acknowledged the infiltration but played down its significance. “Five years ago the FBI informed me it had concerns that an administrative member of my California staff was potentially being sought out by the Chinese government to provide information,” Feinstein said in a statement — which means the breach took place while Feinstein was heading the Intelligence Committee. But, Feinstein insisted, “he never had access to classified or sensitive information or legislative matters” and was immediately fired. In other words: junior staffer, no policy role, no access to secrets, quickly fired — no big deal.

But it is a big deal. I asked several former senior intelligence and law enforcement officials how serious this breach might have been. “It’s plenty serious,” one former top Justice Department official told me. “Focusing on his driver function alone, in Mafia families, the boss’s driver was among the most trusted men in the crew, because among other things he heard everything that was discussed in the car.”

A former top CIA clandestine officer explained to me what the agency would do if it had recruited the driver of a senior official such as Feinstein. “We would have the driver record on his phone all conversations that Feinstein would have with passengers and phone calls in her car. If she left her phone, iPad or laptop in the car while she went to meetings, social events, dinners, etc., we would have the driver download all her devices. If the driver drove for her for 20 years, he would probably would have had access to her office and homes. We would have had the source put down an audio device in her office or homes if the opportunity presented itself. Depending on the take from all of what the source reported, we would use the info to target others that were close to her and exhibited some type of vulnerability.”

“In short,” this officer said, “we would have had a field day.”

All the Russian-spying hoopla is just a distraction from the Chinese spying.