SAN FRANCISCO — With his most public cheerleading yet for California’s bullet train, Gov. Jerry Brown on Wednesday signed the $8 billion bill to kick off high-speed rail construction and showed no sign he was worried about voters’ increasing skepticism for the rail line.

Calling naysayers “NIMBYs,” “fearful men,” and “declinists,” the governor celebrated a project that he first signed a bill to study 30 years ago.

“It’s taken that long to get this going,” he said, flanked by dignitaries and construction workers at the site of San Francisco’s future Transbay Terminal. “You may not be around when it’s finished.”

Brown’s day-long, dual-city signature event began at Union Station in Los Angeles and was followed by the gala in San Francisco. The locations were fitting in many ways since the stations will serve as the two endpoints of the $69 billion line, though Brown had to fly between events.

The centerpiece of SB 1029, however, is $6 billion to start building the first tracks in the Central Valley early next year. The remaining $2 billion will beef up transit while laying the groundwork for high-speed rail in the Bay Area and Southern California, including electrification of the existing Caltrain line between San Francisco and San Jose.

“This legislation will help put thousands of people in California back to work. By improving regional transportation systems, we are investing in the future of our state and making California a better place to live and work,” said Brown, whose signature was only a formality since he led the charge for the bullet train in Sacramento.

Despite the governor’s enthusiasm, high-speed rail has become increasingly unpopular around the state, and polls show a majority of voters now oppose the plan largely because of its record costs and uncertain prospects for completion. Brown, who was silent publicly when the Legislature debated his bullet train plan two weeks ago, now needs Californians back on board but said Wednesday he wasn’t concerned by the polls.

“You have to take the bull by the horns and start spending and investing in things that make sense,” Brown said Wednesday.

His choice of words for the project’s opponents showed the governor wasn’t concerned about winning over critics just yet.

One of those critics, Larry Klein, a Palo Alto councilman and chair of the city’s high-speed rail committee, was unfazed by Brown’s barbs.

“I’m not going to get into a name-calling contest with the governor. That doesn’t get us anywhere,” said Klein, who was not at the signing ceremony. “This doesn’t change anything. It’s still a boondoggle and a fiasco.”

The governor is campaigning for voters in November to approve Proposition 30, hikes on sales taxes and on the wealthy, to raise $8.5 billion and avoid drastic cuts to education and other state services. A recent Field Poll showed some 20 percent of likely “yes” voters on the taxes were less likely to support the measure if high-speed rail got approved.

“That doesn’t mean they’re going to all vote ‘no’, it’s just a negative drag on their early intentions to vote ‘yes,'” Field Poll Director Mark DiCamillo said Wednesday. “It puts those voters in a more vulnerable position — it puts them in play.”

While Brown held nothing back in his remarks on high-speed rail in San Francisco, a press release about his signature was much less candid. It began by saying the bill will “create thousands of new jobs in California by modernizing regional transportation systems” before mentioning high-speed rail.

The press release went into detail on local projects that will benefit from the funds, and how many jobs will be created, without ever detailing the particulars of the high-speed rail project.

Bay Area Democrats, unions and business leaders applauded Brown for improving a wobbling high-speed rail plan in the last year, helping to reduce the most recent cost estimates by $30 billion, speeding up construction and giving funds to the urban areas.

“Governor Brown got this project back on track, changed the course of California history and our region is a big beneficiary,” said Jim Wunderman, CEO of the pro-business Bay Area Council.

The Assembly overwhelmingly endorsed the plan along party lines on July 5, while it passed by a single vote in the Senate on July 6.

Contact Mike Rosenberg at 408-920-5705. Follow him at twitter.com/rosenberg17.