Why have lieutenant governors?

You could say that Gov. Jerry Brown treats Lt. Gov. Gavin Newsom like a dog. But that wouldn't be accurate.

Brown's Pembroke Welsh corgi gets invited into the governor's office practically every day. Sutter gets lots of petting. He regularly walks with gubernatorial aides in Capitol Park.

Newsom essentially gets locked out.

Such is the plight of most California lieutenant governors.

But you'd think that Newsom would be treated better, given the past bonding between his and Brown's families.

Newsom's grandfather was a close friend and campaign strategist for Brown's father, Gov. Pat Brown. He also was the godfather of Kathleen Brown, Jerry's sister. Jerry Brown, the last time he was governor, made Newsom's father an appellate court judge.

"Jerry helped me with my application to Santa Clara" University, recalls Newsom, 45.

But personal relationships are not the 75-year-old governor's specialty. Charm, when it suits. Warmth, no.

Still, Newsom isn't complaining, at least out loud.

"I get it," he says.

Newsom — then the San Francisco mayor — initially challenged Brown for the Democratic gubernatorial nomination in 2010. "I stayed in that race a little longer than he expected or wanted," Newsom says. "So I'm not naive."

After he was elected lieutenant governor, Newsom continues, "it was obvious pretty quickly that this wasn't going to be as easy and seamless as I had hoped."

Newsom told me, in good humor, "You triggered this" by writing a column two years ago praising his authorship of an economic growth plan for California. "It was the kiss of death."

Brown felt that Newsom was trying to upstage him.

The lieutenant governor now concedes that "we got ahead of ourselves on an issue that was not his first priority."

Brown's top priority then was to return state government to solvency. "He's done a magnificent job on that issue," Newsom says. "Trust me, I wouldn't say that if I didn't believe it. I admire the hell out of him."

But Newsom apparently hasn't had a chance to tell Brown that personally.

"I'm ready to take the call and be supportive, whatever he needs," Newsom says. "I really do want to rekindle a relationship, but it's his prerogative."

All this political strain between two Democrats came to mind last week as Newsom assumed the role of acting governor while Brown flew off to Ireland and Germany searching for family roots.

Except that "acting governor" really is a misnomer. Despite the California Constitution's edict that the lieutenant governor "shall act as governor during [the real one's] absence from the state," it hardly ever works that way, particularly in recent years.