Let the great bullet train battle begin.

Even as the California High-Speed Rail Authority unanimously approved the massive project’s final blueprint Thursday, supporters led by Gov. Jerry Brown began a fast-and-furious sales campaign to convince skeptical lawmakers to jump on board.

And the clock is ticking. Only two months remain before the Legislature votes on whether to start building the railroad, a decision that will seal the train’s destiny after 16 years of preparation.

The hearing in San Francisco, a rare Bay Area board meeting for the project, carried little drama, since the rail authority produced the plan. But it provided the agency its only opportunity to defend the latest plan before it begins a gauntlet of what promises to be a grueling series of legislative hearings starting next week.

“After all, this is the Legislature’s decision to fund this or not. I think this provides them with a path going forward that is solid,” said board member Jim Hartnett, of Redwood City.

Board members called the project a wise investment that will save money over the long term and bring the U.S. on par with nations that already have bullet train service. Board Chairman Dan Richard, whom Brown appointed to lead the project, advised lawmakers that building now “is the right thing to do for the state.”

“People will look back, I hope, and say, ‘Thank God they did it,'” Richard said.

Compared with what voters approved in 2008, the new outline doubles the price tag to at least $68 billion, delays the start of service nearly a decade to 2029, slashes expected rider counts, increases fares, shortens the route and reduces train service.

Critics have also questioned whether the new system could meet the legal requirements of the measure voters approved, and opponents speaking at Thursday’s hearing promised more lawsuits. The rail authority still has to decide whether to go above the $68 billion price tag to extend the San Francisco-to-Los Angeles rail line to Anaheim, as promised in years past.

But the most recent business plan is seen as a significant improvement over last year’s strategy, which envisioned a larger, $100 billion railroad that would open in 2034. Some swing-vote lawmakers, particularly, have been at least somewhat impressed, yet it remains to be seen if they can be swayed to support the vision.

In June, the Legislature will vote on whether to start building the $6 billion first leg of construction in the Central Valley this winter, knowing the overall project still has a $55 billion shortfall.

The Democratic leaders of both legislative chambers, Senate President Pro Tem Darrell Steinberg and Assembly Speaker John Perez, and many rank-and-file Democrats support the project as a jobs creator and the transportation option of the future, while most Republicans consider it a waste of money.

Also on Thursday, the board unanimously approved a deal to split with the Bay Area the $1.5 billion cost to electrify the Caltrain line after local agencies endorsed the partnership weeks ago. If the Legislature signs on, construction would begin soon, with electric Caltrains barreling between San Francisco and San Jose by the end of the decade and state bullet trains joining the line some 10 years later.

During the first two hours of the hearing, which featured more than 100 attendees, some 50 backers and critics lobbied the board for about two minutes apiece. The long public comment sessions have become a staple of bullet train board meetings, with Peninsula and Central Valley community groups and conservatives railing against the project, while unions, business groups and transit advocates urge liftoff.

“We’ve come a long way from two years ago; it seems we’re finally moving in the right direction,” said Diana LaCome, CEO of Associated Professionals and Contractors.

Burlingame resident Ted Crocker, co-founder of High-Speed Boondoggle, countered that the new plan was unwisely rushed in response to public outcry over the last strategy.

“When you do something half-assed to save money,” Crocker said before the board, “it will cost you in the end.”

Contact Mike Rosenberg at 408-920-5705.