Bustamante at first vowed to stay out of the recall election, but changed his tune last week, saying he doesn't want his boss' job but is only running as a "worst case scenario."
Bustamante has a somewhat complicated message for voters — vote no on the recall, but in case Davis is ousted, vote for him.
"I'm not running a race that I want to lose. What I am doing is we're trying to make sure that we have plenty of options that we have a serious alternative no matter which way this goes," Bustamante said.
And yet that message may be the least complicated part of Bustamante's relationship with the governor. Davis has said he understands why his No. 2 broke ranks and joined the race. But, he adds, make no mistake, the men who ran for office separately are not close.
"I like Bustamante, I have worked with him. He's been my lieutenant governor [and] has served the people well," Davis said.
"I've spoken to him twice on the phone in the past five years," Bustamante said.
Political observers say the challenge for Bustamante is showing support for Democratic positions while distancing himself from Davis' failures.
The son of an immigrant farmer, Bustamante, 50, grew up to become the state's first Latino speaker of the Assembly and the state's first Hispanic lieutenant governor.
"He's got the kind of experience you need to deal with the tough challenges facing us," said Los Angeles City Councilman Antonio Villaraigosa (search). "It's not just about charisma or sound bites. It's about fixing real problems."
In recent years, Bustamante has fought for stiffer penalties against energy companies that collaborate to raise power prices. He has fought for legislation to ensure diversity at California universities and was a staunch opponent of Proposition 187 (search), a measure that allowed the state to refuse benefits or services to illegal aliens. Voters passed the measure 59-41 percent but it was ruled unconstitutional by the courts.
Even as some conservatives claim Bustamante is racist in his support of Latinos at the expense of other groups, Bustamante's heritage and pro-immigration stance could help rally California's increasingly powerful Hispanic vote
But in California, getting votes means buying radio and television airtime. Unlike some of his deep-pocketed opponents, Bustamante lives off a politicians' salary.
He may have a fund-raising ace in the hole — California's Indian tribes. Bustamante has long supported casino gaming and they could be a rich source of funds for his campaign.
The latest ABC-7 Los Angeles poll of 575 registered voters showed Arnold Schwarzenegger leading the polls 51 to Bustamante's 17 percent. Given Schwarzenegger's commanding lead, Bustamante's supporters may think twice about betting the house on an underdog.
Fox News' Trace Gallagher contributed to this report.