WASHINGTON — Republicans are lying when they say that members of Congress who support the clean energy bill are backing an “energy tax.” There is no such tax. There will be costs, though, and absolutely nobody knows what they will be.

That’s just one reason why the 1,200- page American Clean Energy and Security Act is a mighty hard bill to vote for. Another is that it is a monster, driven in part by zealots, that creates new networks of expensive and conflicting bureaucracies. It is not just another Clean Air Act. The measure touches almost every aspect of private life in the United States except human sexuality and pet grooming.

Controls on so-called greenhouse gas emissions would be imposed on factories, cars, office buildings and electric utilities, in fact on every activity that uses any form of coal or oil or natural gas, directly or indirectly.

If enacted, it becomes another tool with which Washington can tell industry what cars and appliances to make.

Guesstimates of the cost on households and businesses vary wildly, and are as reliable as the 1965 prediction that Medicaid would cost only $25 billion a year. Agencies that support the bill like the Congressional Budget Office say it will cost each household only $175 a year in higher electric and heating bills.

The Heritage Foundation, which doesn’t like it, forecasts $1,750 per household. President Obama’s Environmental Protection Agency pegs the cost at $80.

It’s all for good environmental and political causes. The program promises to dramatically cut carbon dioxide emissions that contribute to global warming and disease, and reduce U. S. reliance on oil from regimes that hate us.

Passage would add another Democratic rebuke to the oil-loving Republican Bush administration that arrogantly thumbed its nose at world treaties on pollution.

Republicans are calling the climate bill a “job killer” because of the unforeseen effects of energy price increases and a whole complex of government regulations on businesses amid a deep recession.

Who can tell? Certainly not your neighborhood member of the House or Senate. What will be the effect on business of such new agencies as the U. S. Carbon Storage Research Corp., the Clean Energy Innovation Centers, the Centers for Energy and Environmental Knowledge and Outreach, the National Bioenergy Partnership, the Electric and Thermal Waste Energy Recovery Awards, the U. S. Global Change Research Program, the Climate Change Health Protection and Promotion Fund and the National Resources Climate Change Adaption Panel? Huh?

Only the lobbyists know for sure. In the run-up to last weekend’s House vote, the Democratic majority mimicked the discredited GOP one, 1995-2006, by making passage a test of their “ability to govern,” by stringing out the voting time and by peeling off opponents one by one.

Eliminating cow dung from emission controls assuaged farmers. Rust Belt members were told exporting countries like China and India that didn’t control carbon dioxide would suffer trade penalties, as though we’ve ever enforced trade sanctions.

Friends of the Earth charged that some involved in drafting the bill, including Shell Oil, Dow Chemical and DuPont, were offered concessions on emission controls. The group said the EPA’s powers to curb global warming were savaged.

With the Capitol quivering in righteousness, serious concerns about the worth of the bill and its business effects are junior to political worries about a voter backlash against legislative overreach. But the Democrats didn’t worry about the 1993 tax bill or the 1994 health care fracas that led to the GOP House takeover in 1995, any more than the GOP thought about reactions to the doughnut in Medicare Part D before they lost in 2006.

The House vote is only the first test. It has to clear the Senate and then come back to both houses for a vote on a conference report.