The camera pans through the dark, grim corridors of an old-age home. A woman sits in a wheelchair -- motionless, neglected. Off-screen, feeble voices implore, "I just want some water" and "Someone, help me." The announcer attacks "some people in government" who favor "cutting back on care for our most vulnerable citizens."

"America," the announcer exhorts. "It's time for new priorities."

So goes a 30-second television message produced for the American Federation of State, County and Municipal Employees (AFSCME) as part of a $1.2 million ad campaign. Launched last summer in several presidential primary or caucus states, it is an early attempt, as AFSCME spokesman Phil Sparks put it, "to move the political barometer."

Several interest groups are waging or planning similar campaigns. In this case, the million-member government employes' union wants to persuade voters and candidates that "government is not the bad guy," but rather "an innovator in helping to improve the quality of life," Sparks said.

Televised attempts to alter the atmosphere are not new in presidential politics. But in the last two presidential election cycles, they have generally been the province of conservative groups such as the National Conservative Political Action Committee (NCPAC). This time, the television effort has been been nominally nonpartisan. As the race heats up, much of it will probably come from labor unions and foundations.

"The right wing has run out of ideas and money," Sparks said, "and we're the ones behaving more like they did in 1979. We're trying to shoehorn our ideas into the next presidential campaign and use, in a very sophisticated way, the electronic media."

"I think what you have is one of those moments in American history -- very clearly a moment in which we're seeking a new national agenda," said Arnold Bennett of the senior-citizen-oriented Villers Foundation, which is producing five-minute television shows on long-term care to be aired in Iowa. "Just about everybody recognizes that we're now looking at a blank page in the post-Reagan era."

"I think that's probably true," said conservative direct-mail fund-raiser Richard Viguerie. "The president has retired from the field of battle. He has left a level playing field with nobody commanding the Republican conservative troops. If the left pushes hard right now, they'll meet with a fair amount of success until the conservatives come up with opposition."

"We can't raise money through government grants and dues checkoffs," said Howard Phillips of the Conservative Caucus. "We have to do it the old-fashioned way. We earn it."

Last week, Viguerie and Phillips unveiled the Anti-Appeasement Alliance, an ad hoc collection of conservative groups formed to counter the Reagan-Gorbachev summit and to oppose "communism, socialism, liberalism and big government," as Viguerie put it. Still, he said "it's too early" to think about buying television time.

"None of them has enough money," political ad specialist Michael E. Murphy said of the conservative groups. "The driving forces don't seem to be there anymore. As a conservative, I feel kind of sad."

AFSCME, however, appears to have plenty of money. Sparks said the union plans to spend $250,000 next month to buy television time in Iowa, New Hampshire and Minnesota. And People for the American Way, which ran television spots against the confirmation of Supreme Court nominee Robert H. Bork, is gearing up for an ad campaign against government censorship and secrecy, said president Art Kropp.

The 27 million-member American Association of Retired People, through its "AARP/Vote" project, has been waging a $400,000 television effort in Iowa, Maine and New Hampshire, urging voters to pin candidates down on issues such as health care for the elderly and retirement-income security. AARP/ Vote's Kevin Donnellan said $5 million has been budgeted for television time and related voter-education efforts next year.

One 30-second message features a candidate desperately trying to waffle out of harm's way as participants in a town meeting zing him with questions about rising health-care costs and the inadequacy of Medicare. "Uh, well, I'm looking into it," the hapless candidate sputters, as his aide in the audience goes wide-eyed with panic.

"Go ahead. Ask them," the announcer intones. "Then vote."