McCain joked about the health of his campaign Tuesday.

BURBANK, California (AP) – Republican presidential candidate John McCain said Tuesday the public is yearning to hear the truth from politicians, and he didn't spare his troubled campaign from a critical self-appraisal.

"We are doing so poorly I thought maybe I would announce on this show that I'm running for president," McCain told Jay Leno in an appearance taped for broadcast Tuesday night on "The Tonight Show."

"We have obviously made mistakes," the Arizona senator said.

Lagging in fundraising and national polls, McCain said he was relishing the underdog's role and remained enthusiastic about his chances in 2008.

Americans "are looking for someone who will tell them the truth, whether they happen to like to hear it or not," he said.

"I think too often politicians tell them what they think they want to hear, rather than what they believe."

McCain turns 71 Wednesday — if elected he would become the oldest first-term president. Leno mentioned the birthday and McCain noted that his 95-year-old mother was refused a rental car in Paris because of her age.

So she bought a car and drove around sightseeing.

"I'm taking her with me wherever I go," McCain said.