The conventional thinking is that Bill Richardson is running a great campaign — for vice president.

At least that's what you hear from Sunday-morning pundits in Washington who insist on framing the Democratic primary race — and for that matter, the Republican one — as a two-person contest.

So during a quick phone interview while he was on the campaign trail in Iowa, I asked the New Mexico governor if he was really auditioning for the No. 2 spot.

"That's baloney," Richardson said.

What else is he going to say? No presidential candidate openly campaigns for the second- highest elective office. So I asked him if he'd take the job if it were offered and if there was anyone among the top candidates — Hillary Clinton, Barack Obama, plus John Edwards — with whom he couldn't see himself sharing the ticket.

"You know," Richardson said, "I'm really not interested. I'll come back to be governor of New Mexico, a job that I love. I can do my foreign policy ventures. I'm really not running for that."

According to some polls, more and more Democrats are showing an interest in Richardson. His poll numbers are up in some of the early states. The candidate credits "intensive personal campaigning" and his debate performances where, on immigration and foreign policy, he was — as he puts it — "strong and firm and didn't deviate."

He may be onto something. In both the Democratic and Republican contests, one gets a sense that voters have become pretty skilled at ferreting out which candidates believe what they're saying and which ones are just saying what voters want to hear.

According to a Washington Post/ABC News poll, Richardson gets points on immigration. Twenty-five percent of Americans trust him on that issue — a better showing than his opponents.

Why is that?

"It's because I'm honest," he said. "And when I'm asked to explain my position in Iowa and New Hampshire, generally audiences that may be a bit hostile, I say to them that I'm for more security at the border, but I'm not for the wall. I say that it makes sense to have a legalization plan. What are the options? Deportation, or doing nothing?"

On the trail, Richardson even has a dependable applause line to deflect hostile questions. In a country where everyone likes to bellyache about illegal immigration — but few want to take responsibility for it — sooner or later the conversation comes around to the convenience of blaming Mexico.

He tells crowds that we should be "speaking frankly with our friend Mexico" and demanding that the Mexican government do more about poverty or, at least, "stop handing out maps of the easiest places to cross."

Richardson also thinks that Clinton, Obama and Edwards are bungling the immigration issue because they're "trying to duck it with rhetoric" when this is an issue that can't be finessed.

"The impression they're giving," he said, "is that: 'This is too hot to handle. I'll retreat to niceties and broad general statements.' "

Worse, he said, the GOP has created an opening that few Democrats are taking advantage of.

"There's an opportunity because Republicans are being totally reprehensible about it and nativist," he said.

Good for him. Edgy comments bring to mind the personal balancing act that one has to strike when he's the first credible Hispanic candidate for president. How do you appeal to the mainstream but stay true to your ancestry?

"I'm very candid," he said. "I say, 'Look I'm not running as a Hispanic candidate. I'm running as a Western governor, proud to be Hispanic but I don't wear my Hispanic-ness on my sleeve."

In fact, with a name such as Richardson, which comes from his American-born father, it's possible that many Hispanics don't even know that Richardson is one of their own.

The candidate says that is one reason he began "Mi Familia con Bill Richardson," an outreach effort aimed at Hispanic voters — a group that will leave a huge footprint on Feb. 5 when votes are cast in heavily Hispanic states such as California, Colorado, Arizona and Richardson's home base of New Mexico.

"My strategy is simple," Richardson said. "It's to end up in the top three in Iowa, top three in New Hampshire, top three in Nevada. If I do that, then I'm on my way."

Yes, but to where — and to which office?

Ruben Navarrette Jr., is a columnist and editorial board member of The San Diego Union Tribune. Reach him at ruben.navarrette@uniontrib.com.