The theme was a centerpiece of President Reagan's 1980 campaign: it was time the federal government turned back authority to the states, time to let Albany and Tallahassee, Springfield and Sacramento have their say.

Now, nearly two years after Reagan's election, the states have more control of programs giving aid to the poor, training workers for jobs, building subway systems and controlling air and water pollution, though often less money to spend for them. But some moves initiated or encouraged by the administration would take powers away from the states, rather than return them.

Across a variety of issues, the administration has put its muscle behind efforts to preempt the regulatory role of the states. For instance:

* Environmental Protection Agency officials went to Capitol Hill earlier this year to support legislation to give the states authority to gather more information about new pesticides than the federal government. But, after lobbying by the pesticide industry, the Office of Management and Budget sent word to the Hill that the administration had changed its mind, it didn't want the states doing anything that would conflict with Washington's rules. Opponents of the preemption provisions in the legislation believe they have won this round, but expect a tough fight next year.

* The Interior Department last year lost a court battle with California over the extent of the department's obligations to abide by requirements of the state's congressionally approved coastal management plan. The administration argued that selling leases on offshore oil tracts did not "directly affect" the California coastline. Two U.S. courts disagreed.

* The Energy Department, required under Carter-era legislation to set a uniform national standard for the efficiency of major home appliances, earlier this year proposed a "no-standard standard," saying the federal government would not tell manufacturers how energy-efficient their products had to be. Under the law, the "no-standard standard" would preempt statutory standards in half a dozen states and building code standards in more than 40.

Administration officials are quick to point out that preemption debates have been around since long before Reagan took office, and were often more acrimonious when the Democrats were in power. Other observers note that the arguments this time look like a photographic negative of the state-federal disputes of the 1960s and 1970s. Now it tends to be the more liberal statehouses, in places like California, New York and Wisconsin, arguing with a more conservative federal administration.

But like most generalizations about preemption, that doesn't necessarily hold. Especially on land-use and energy-development questions, some of the more conservative state governments, particularly in the West, have had the sharpest disagreements with Washington.

How does the administration reconcile these actions with states' rights rhetoric? Rich Williamson, assistant to the president for intergovernmental affairs, said: "The heavy presumption is against federal preemption. But there are circumstances where that presumption can be overcome. Decisions are made on a case-by-case basis."

"They use the states' rights argument throughout, unless the interests of industry interfere," said a staff worker for a northeastern state's Washington office.

"Sometimes, when it comes to a choice between states' rights and the commerce clause of the Constitution , this administration loses its states' rights orientation," Joseph Kinney, director of agricultural issues for the National Governors' Association, said.

But other administration actions run counter to that view, including its opposition to legislation introducing federal controls for state and local governments' employe pension plans, and its decision to settle a New Jersey lawsuit and allow Trenton to tax toxic waste producers to maintain a fund to clean up toxic waste dumps in specified circumstances. The fund is analogous to EPA's "Superfund," though the legislation creating the "Superfund" seemed to bar states from taxing industry for the same purpose.

And even the energy efficiency issue may prove to be an example of Reagan administration support for state authority.

Kay Henry, an Energy Department lawyer, said last week she expects the department to be liberal in giving states waivers from the federal standard; in other words, letting them set energy efficiency standards of their own. The effect could be the appliance manufacturers' worst nightmare: when marketing their products in different states they would have to meet different standards.

Robert C. Odle Jr., an assistant energy secretary, said last week he recognized industry's difficulty but, "We're taking a consistent position. We don't believe government standards are a good idea, so we don't want to impose them. If the states do, that's their business. We would prefer the statute requiring energy standards and requiring preemption of the states did not exist and at an appropriate time we will ask Congress to repeal it . . . . The federal government shouldn't be setting standards. That should be done in the marketplace."

The National Conference of State Legislatures just completed a scorecard on preemption questions in Congress and found the administration's policy to be inconsistent. Mary Jane Gallagher, the group's public information officer, said, "It seems to be a random process; they came down on the sides of the states and they came down on the side of industry." But in nine of the 12 instances, it supported moves to take regulatory powers from the states.

The final factor in determining whether the administration pushes for preemption, observers said, appears to be the internal politics of an issue. Sometimes its philosophical predisposition for states' rights wins out over the needs of industry, but sometimes industry is able to persuade the administration that its needs are more important than those of state governments.

What seems to make the difference? Generally the political muscle of the industry involved, they said.