THINGS JUST WENT from bad to worse for high-speed passenger rail in California. After the Golden State’s voters approved a $9 billion bullet-train bond issue in 2008, officials said they could build an 800-mile system by 2020, for $35.7 billion. The cost projection now, as issued by the state Nov. 1: $98.5 billion, with a completion date of 2033.

Time to pull the plug, right? Not according to Gov. Jerry Brown (D). The new “business plan is solid and lays the foundation for a 21st-century transportation system,” he said. Equally upbeat, Transportation Secretary Ray LaHood offered Mr. Brown his congratulations on “a sound, step-by-step strategy for building a world-class high-speed rail network.”

This is unreal. Apart from the bond issue and $3.6 billion in federal funds already in hand, the cash-strapped state hasn’t credibly identified a source of funds for the system. The new report basically repeats previous assertions that, if California builds, federal and private-sector dollars will come. This is wishful thinking in an era of massive federal deficits, and if the opportunities for the private sector were really so great, where are the companies clamoring to invest?

Actually, the gigantic cost estimate amounts to an indirect confirmation of the doubts voiced in several independent analyses, which have focused on not only the rail plan’s mythical funding but also its high ridership projections — and the attendant risk that California will get stuck with expensive operating subsidies as well as billions in debt service.

Of course, that risk would occur only in the decreasingly probable event that California actually finishes the railroad. A more plausible scenario is that the state manages to construct merely a line between two points in the rural Central Valley before its cash peters out.

Why? The Obama administration has made clear that the state will lose $2.3 billion in federal funds unless it starts construction by October 2012. The money comes from the 2009 American Recovery and Reinvestment Act — the stimulus bill — and that law’s purpose was to get people to work, pronto. The deadline is inflexible.

Alas, there is only one place where the state could finish the necessary environmental impact statements and other bureaucratic requirements before the use-it-or-lose-it date: a thinly populated 130-mile stretch of flatland that starts just north of Fresno and ends just north of Bakersfield.

U.S. and California officials tout this lonely corridor as the “spine” of a system that will connect big cities later on. After all, they argue, the interstate highway system started in Kansas. But that project had a dedicated funding source from the get-go: the federal highway trust fund, supported by fuel taxes.

More realistically, Sacramento’s Legislative Analysis Office calls the Central Valley starting point a “big gamble.” In the all-too-likely event that funding for the rest of the system never materializes, the report adds, “the state will be left with a rail segment unconnected to major urban areas that has little if any chance of generating the ridership to operate without a significant state subsidy.” It would be a train to nowhere, but at least it would go nowhere fast.

As questionable as this project is, we would have less business objecting if the only money at risk was California’s. But the Obama and Brown administrations are talking about devoting the nation’s funds to what looks more and more like a boondoggle. If the president and governor won’t slam on the brakes, then Congress or the California legislature must find a way to prevent the spending. Somebody, please, stop this train.