SACRAMENTO — Across the country, the era of ambitious public works projects seems to be over. Governments are shelving or rejecting plans for highways, railroads and big buildings under the weight of collapsing revenues and voters’ resistance.

But not California.

With a brashness and ambition that evoke a California of a generation ago, state leaders — starting with Gov. Jerry Brown — have rallied around a plan to build a 520-mile high-speed rail line from Los Angeles to San Francisco, cutting the trip from a six-hour drive to a train ride of two hours and 38 minutes. And they are doing it in the face of what might seem like insurmountable political and fiscal obstacles.

The pro-train constituency has not been derailed by a state report this month that found the cost of the bullet train tripling to $98 billion for a project that would not be finished until 2033, by news that Republicans in Congress are close to eliminating federal high-speed rail financing this year, by opposition from California farmers and landowners upset about tracks tearing through their communities or by questions about how much the state or private businesses will be able to contribute.

The project has been mocked by editorial boards across the country — “Somebody please stop this train,” The Washington Post wrote — while Republicans here have denounced it as a waste. In an unfortunate turn of timing, state officials announced this month that revenues this year were so far behind projections that California was likely to have to impose $2 billion in cuts in January.