Fiercely independent rural Oklahomans are demanding protection against cheap imported beef and Mexican glass. Silicon Valley's high-tech firms rail against restricted Japanese markets. And southern clothing makers and timber barons warn that foreign competition is driving them under.

The once-isolated call by aging steel mills and rust-belt automakers for government action against low-priced imports and unfair foreign trade laws has begun to sweep every part of the country, turning Sunbelt free-traders into protectionists and making trade -- and the record $150 billion trade deficit -- the top political issue in Congress.

It has put President Reagan and the Republicans on the defensive as complaints mount that Reagan's free-trade policies have caused a hemorrhaging of U.S. jobs to other countries. And it has given Democrats their first solid issue for 1986, one that could entice southerners and blue-collar workers back into the fold. It is an issue that attacks Reagan on his own turf by appealing to American nationalism.

"It's a little bit like the Iranian hostage crisis in reverse: Who's going to stand up for America and not let us get kicked around?' " said Rep. Dick Cheney (R-Wyo.), a member of the House Republican leadership and a committed free-trader.

"It's a powerful issue for us because it impacts on the areas that the Republicans have been expanding in -- the South and the West," said one Democratic congressional official. "It's a jobs issue -- we're protecting jobs. And at the same time, it's a nationalist issue."

Rep. Tony Coelho (D-Calif.), head of the Democratic Congressional Campaign Committee, said, "If we can't deal with other countries on the trade issue, then we're weak. It becomes a Democratic macho issue. We're for American strength."

The partisan potential of the trade issue was brought home to the Democrats during the special election in Texas' conservative First Congressional District. Outspent more than 2-to-1 by the Republicans, the Democrats nonetheless eked out a victory in the race after attacking the GOP candidate for saying he did not see what trade policy had to do with jobs in east Texas.

Since then, "Texas One," a reference to the race in that congressional district, has become a Democratic mantra in nearly all discussions of the trade issue.

The Texas outcome sent a strong message to the Republicans, too. Returning from the August congressional recess in a rebellious mood, GOP leaders publicly warned Reagan that continued Republican control of the Senate could be at stake, and they threatened to move on the issue without him if he did not quickly come up with a tougher trade policy.

Last week, Reagan relented and agreed to work with Republican congressional leaders on a trade package that would ease pressures on U.S. businesses but without protectionist measures strongly opposed by Reagan.

Even with the details of the White House package still unwritten, Republicans and Democrats agree it is unlikely to go far enough to cool growing bipartisan sentiment for tough trade action on Capitol Hill.

Many Republicans are clearly not in the mood to adhere to their party's traditional free-trade posture. House Minority Leader Robert H. Michel (R-Ill.) bluntly told Reagan last week that if the package is not tough enough, "our members are of such a mind to do a little bit more."

Rep. Edwin V.W. Zschau (R-Calif.), one of those who has not joined the protectionist bandwagon, said last week, "Republicans don't want to be seen as sitting on their hands because this could be a key issue in 1986. The politics of it is the most powerful force, not the logic of it."

Zschau said several of his GOP colleagues at a recent lunch were so concerned about the potential political repercussions from the trade issue that "it was almost driving them to adopt the Democrats' [protectionist] approach. They said, 'yeah, we know this is wrong, but we can't be viewed as doing nothing.' "

Many Republicans have sponsored or cosponsored the 300 or so bills that have been introduced to punish Japan and other trading partners or to protect certain industries, from shoes to textiles. The textile bill, which would slap tough new quotas on clothing and other textile imports, is perhaps the most popular and is being cosponsored by more than half the lawmakers in the Senate and House, including dozens of Republicans.

Reagan has threatened to veto the measure on the grounds that it would spark a trade war that would hurt American consumers. But House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) and Senate Majority Leader Robert J. Dole (R-Kan.) agreed last week the textile measure is likely to be approved by Congress.

Privately, some Democrats who oppose the measure say they hope Reagan does veto it, giving the Democrats a rallying cry in southern states where textile layoffs have caused growing unemployment problems.

The Democrats are planning this fall to send congressional brigades sporting "Democrats Give a Damn" buttons to southern states affected by textile imports and to the Midwest, where farmers blame the administration's farm and trade policies for their many woes.

"It's a great one-two punch in the Midwest," Coelho said. "It's the type of thing, as we proved in Texas One, where people are going to come back home" to the Democratic Party.

But, while the Democrats agree on the political wisdom of attacking Reagan's lack of aggressiveness on trade, they remain divided over how far Democrats should go in pushing trade legislation.

Some support immediate tariffs and quotas for specific industries. A few Democrats, such as Sen. Gary Hart (D-Colo.) say they think that it would be "tragic" if Reagan were "let off the hook." But it would be equally dangerous for Democrats to push through protectionist measures to satisfy one group or industry, Hart said.

"The short-term reward, if Democratic-led legislation were to be enacted that got tough on the Japanese and others, is that those most affected would say, 'well, at least the Democrats did something,' " Hart said. But quotas would provoke retaliation, and a trade war would ultimately hurt consumers and bring blame on the Democrats, he said.

Hart said he will propose a trade bill in the next week, focusing on trying to reduce the overvalued dollar, expand markets in the Third World and toughen some existing remedies for unfair trade practices.

The Democratic proposal that appears to be garnerning the most support is a bill sponsored by House Ways and Means Committee Chairman Dan Rostenkowski (D-Ill.), Rep. Richard A. Gephardt (D-Mo.) and Sen. Lloyd Bentsen (D-Tex.), who like many of his southern colleagues only recently left the free-trade fold. Their bill would force Japan and other countries to reduce their trade surplus with the United States or face a possible 25 percent tariff on goods sold in this country.

Gephardt said last week that while he supports open markets and free trade, "we have been on the losing end of that . . . . I think Congress has to put a limit on the hemorrhage.