The politics of trade, in all its national and regional dimensions, produced some odd alliances last week.

President Reagan and one of the many men who hope to succeed him, Sen. Gary Hart (D-Colo.), found themselves in rare agreement. Both denounced as "protectionist" the far-reaching trade law revision legislation that swept through the Democratic-controlled House. Reagan said the bill was "antitrade" and "rankly political." Hart approvingly quoted Republican descriptions of the measure as "a turkey."

But on the House floor, where politics tend to be purely local, it was a different story. Rep. Tony Coelho (D-Calif.), chairman of the Democratic Congressional Campaign Committee, and Rep. Howard Coble (R-N.C.), whom Coelho has targeted for political extinction next fall, voted for the bill.

The different positions, crisscrossing party lines, reflect an ongoing debate over the political potency of the trade issue. That debate is most intense in the Democratic Party, which is groping for national themes on economic growth to take into the 1988 presidential election while it battles this year to regain control of the Senate and widen its majority in the House.

When Hart called the Democratic bill an example of "the new protectionism," he was viewing the issue from the perspective of 1988 and a possible national campaign. Democrats have been warned that by embracing tough trade legislation, including tariffs and quotas, they risk being labled the fearful, "protectionist" party of the past, while the Republicans stand tall as the optimistic prophets of America's economic strength and competitiveness.

On the national level, the issue is "deadly," said Democratic political consultant Harrison Hickman.

But this is 1986, not 1988, and the coming political battles will be local and regional, not national. In North Carolina this year, said Hickman, the trade issue could help former Democratic Gov. Terry Sanford defeat Rep. James T. Broyhill (R-N.C.) in the race to succeed retiring GOP Sen. John P. East.

Trade may be an issue in other states and regions, but nowhere will the stakes be higher this fall than in North Carolina, where the state's venerable textile industry has been battered by foreign competition. That alone helps explain why all five GOP House members from North Carolina voted for the Democratic trade bill along with Coelho, whose job it is to defeat Republican House candidates.

The Sanford-Broyhill race is viewed as one of several that ultimately could determine control of the Senate, which the Republicans now hold 53 to 47.

In the House, all five North Carolina Republicans are to some degree in danger. Broyhill is giving up a safe seat to make a statewide race, while his four GOP House colleagues are all freshmen, elected by razor-thin margins during the Reagan landslide of 1984, who now stand at the top of the Democrats' 1986 hit list.

If the Democrats are to make significant gains in their House majority this year, they will have to begin in North Carolina.

Coelho is betting they will, and that trade, with its links to failing industries and joblessness, will be an important factor in a number of races there and elsewhere this fall. He has been trumpeting the issue since last summer, when Democrat Jim Chapman won a special congressional election in Texas against a GOP opponent who said he failed to see the connection between international trade and prosperity in east Texas.

"Do you think we have them on the run a little bit?" said Coelho in noting that 59 House Republicans defied Reagan and supported the Democratic trade bill. These included not only the "North Carolina Five," but two of the three Republicans from South Carolina, all three from Connecticut, both GOP House members from Maine and eight of Pennsylvania's 10 Republicans.

The roll call of GOP defectors traced a trail through some of the most economically hard-pressed regions of the country.

The North Carolina Republicans are not about to make the mistake of Edd Hargett, the defeated GOP candidate in Texas. Last December, they strongly supported legislation to protect the textile industry, which Reagan vetoed. When the veto comes up in the House in August, they are expected to vote to override the president.

Like numerous Republican lawmakers from economically depressed farm states, they have distanced themselves from the Reagan White House on an issue of particular concern back home.

The Republicans say they are trying to "send a signal" to the administration.

"I am without question pro-Ronald Reagan," said Coble, one of the freshmen lawmakers. "But I'm disappointed in the area of trade."

"I'm not all that happy about what we're doing," Broyhill said of the House trade bill. But he added, "the perception out there is that the administration wasn't doing enough."

There is no question that, in North Carolina at least, the Republicans are on the defensive on the issue. Andy Frazier, executive director of the state GOP, said trade policy "is an issue of concern to us," although he said he doubted it would be "that damaging." His counterpart at state Democratic headquarters, Ed Turlington, was far more enthusiastic.

"This is going to be a crucial issue," Turlington said. "It could be the swing vote in three [congressional] districts and the Senate race."

Sanford has attacked Reagan administration trade policies in his early broadcast commercials. He and other Democrats will pound on Broyhill and his GOP colleagues for failing to persuade a Republican administration to be more responsive to the economic hardships caused by the trade imbalance.

After almost six years of political dominance by Reagan, North Carolina Democrats are hungry for the chance to take on the GOP on an issue of their choosing.

"This is the kind of issue that can send a message to all those nouveau Republicans in the South that their gods have let them down and they better return to the religion of their forefathers," said Rep. Charlie Rose (D-N.C.).

Broyhill said he hopes the fall elections will turn on more than North Carolina's troubled textile industry and that Reagan and Republicans in general will be seen as responsible for overall economic recovery.

"If things are going well, if plants are working, the jobs picture is good and the farm situation is better, Republicans will do well," he said. "If not, we'll get wiped out."