For the last seven years, American politics has been stuck on the painful question of whether to let domestic oil producers have the full benefit of the huge increases in world oil prices set by the Organization of Petroleum Exporting Countries (OPEC).

Now a new reality is emerging. It appears that the oil companies have ground down the opposition. They have won.

Federal price controls are on the way out, which means additional energy price increases lie ahead. And Congress does not seem disposed as it once did to impose a heavy "windfall profits" tax on oil producers.

President Carter helped push through Congress last year a bill to lift price controls on natural gas, and now has begun to lift controls on domestically produced oil as well.

The House last week turned aside almost casually a proposal that oil controls be reimposed. The vote was 257 to 135.

A citizens group boasting on its letterhead such powerful member oranizations as the Auto Workers, the Machinists, the State, County and Municipal Employes and the National Council of Senior Citizens, tried to stage a national day of protest this week. The turnout was spotty.

The leading politician still nominally in favor of controls is Sen. Edward M. Kennedy (D-Mass). President Carter's likely challenger for next years Democratic presidential nomination.

But Kennedy has done little flailing on this issue of late, and aides say one reason is that he recognizes congressional sentiment has shifted. Controls are a loser.

Says Sen. Henry M. Jackson (D-Wash.), chairman of the Energy Committee and longtime battle for controls: "Very candidly, we don't have the votes."

"The problem," adds Rep. Bob Eckhardt (D-Tex.), a leader of pro-control forces in the House over the years, "is that now we have Democratic president against us, and you can't fight both a Democratic administration and the consolidated force of the Republican opposition. We [Democrats] have no leader we can rally behind."

But others, including many who regret the rising prices, say the problem is more complex than this, not just a question of leadership and political will.

They say controls are not workable, that the U.S. market is too large to be artificially administered, that the government in the end has had no choice but to yield to the world price levels.

Says Rep. James R. Jones (D-Okla.), an increasingly influential House member who favors decontrol: "The consensus in the House is that controls will work for a short period of time, say for less than a year, but long term, they are a disaster."

There is also the powerful argument, heard in the Nixon and Ford administrations as well as Carter's that higher energy prices are in some ways good for the country. They stimulate increased domestic production. At the same time, they help deter consumption in a country that uses more energy per capita than any other in the world, more than many believe is good for it.

Indeed, some suggest that the whole strategy of the last seven years has been merely to stretch out this adjustment, make it gradual, so as not to have too politically painful a loss in living standards all at once.

Politicians in oil-importing countries all over the world have been seeking such stretch-outs.

That is what Congress had at least partly in mind when it decided to extend oil price controls in 1975. Even as voted then, controls would have phased out gradually. President Carter this year has merely speeded up that process.

In the 1975 debate, Rep. John D. Dingell (D-Mich.), then as now a supporter of controls, said that sudden decontrol would "stimulate a new round of inflation . . . cut housing starts by 160,000 units and automobile production by 750,000 cars, and cost and additional and unnecessary loss of half a million jobs."

Such arguments prevailed then, but now seem to have lost their force. One reason may be that the country has now grown more accustomed to the higher energy prices. They are less of a shock today.

While abandoning controls, the politicians -- this mainly applies to Democrats -- have not abandoned their habit of attacking the oil companies.

The argument could be made that Carter -- by moving to lift controls from both natural gas and oil -- has done as much for the oil companies as any president in recent memory.

Carter has, however, proposed a windfall profits tax.

And in the meantime, he has been vigorous in denouncing the companies, particularly what he has called "their enormous authority and influence . . . in the Congress."

Kennedy, too, has indulged in anti-oil rhetoric.

The United States cannot credibly attack OPEC's price hikes," he has said, "if it is willing to give domestic producers the same excessively high rates."

And a few weeks ago he told a group of security analysts in New York that "now is not the time" for oil decontrol.

But decontrol began last summer. It will add billions of dollars to oil company revenues over the next 10 years -- nearly $30 billion in just 1980 and 1981, according to one recent analysis.

And even Democrats are evenly divided. On last week's proposal to reimpose oil controls, 120 Democrats voted no, 128 aye.