There was a time in American politics when the problem of Taiwan seemed relatively simple. In those days liberals behaved like liberals and conservatives behaved like conservatives.
Now there is a hint of change.
For the first time, representatives of a conservative administration appear to have given a high-level hearing to a delegation of four Taiwanese politicians whose patrons would previously have belonged more exclusively in the liberal ''pro human rights'' camp.
This delegation of Taiwan-born legislators favors a greater voice on Taiwan for the native Taiwanese, who make up some 80 percent of the island's 18 million people. Taiwan is dominated under martial law rule by the less than 20 percent ''mainlander'' population that fled to Taiwan after the communist victory on the mainland in 1949.
Like most of the ''mainlander'' minority, most native Taiwanese oppose rule by Communist China.
The four Taiwanese politicians met earlier this month with high-level State Department and White House officials, according to sources close to the delegation.
The delegation is said to have met with Assistant Secretary of State for East Asian and Pacific Affairs John H. Holdridge and his deputy, Thomas Shoesmith. The group also saw Deputy Assistant Secretary of Defense for East Asian and Pacific Affairs Richard L. Armitage, as well as Gaston Sigur of the White House National Security Council, according to the sources. A State Department spokesman, however, pointedly declared he ''could not confirm'' the talks.
''The State Department and the International Communications Agency would like to keep a low profile on this, probably to avoid agitating the People's Republic of China,'' said Robert Lai of the North American Taiwanese Professors Association, which sponsored the visiting delegation. Mr. Lai contends that even such low-keyed high-level contacts will convey two messages from the United States:
* The first, perhaps not surprising from a conservative administration committed to the defense of Taiwan, is a message to Peking that the US has not abandoned interest in the future of the island's people.
* The second, directed to the Nationalist government on Taiwan, is that the Reagan administration is concerned about the island's Taiwanese majority, as well as about the mainlainders' minority. In a quiet way, the US thus suggests that even a conservative administration has distaste for any human rights violations in Taiwan, according to Lai.
The visit by the four native Taiwanese politicians is the first of its kind by high-ranking native Taiwanese leaders who are independent of the ruling Nationalist Party. Previously, native Taiwanese politicians did come individually. They, too, carried a hint of official interest because they, like other visitors from all over the world, were sometimes sponsored by the US International Communications Agency.
This time the ICA sponsored the group's July 10 to 15 stay in Washington. Talks with China specialists and local Taiwanese were held in San Francisco, Houston, Knoxville, Chicago, and Los Angeles.
The delegation was made up of three national legislators: Chang Te-Min, Huang Huang-Hsuing, and Kang Ning-Hsiang, as well as Yu Ch'ing, a member of a central watchdog body known as the Control Yuan. All are well known in Taiwan as elected officials who work ''within the system'' to gain greater benefits for the Taiwanese majority. They are relative moderates. More radical native Taiwanese have sometimes been arrested and, by some accounts, tortured for organizing or agitating against the Nationalist Party.
In earlier days, native Taiwanese politicians, intellectuals, or activists in exile gained little attention. And the attention they gathered was predictable.
Liberals often looked sympathetically on anyone claiming that Chiang Kai-shek's government of mainlanders was an authoritiarian violator of human rights, and contrary to the wishes of the majority Taiwanese people. It was hoped that criticism of the Chiang Kai-shek government would speed the way to ties with Peking.
For conservatives it was nearly unthinkable that anything challenging Chiang Kai-shek's democratic credentials be taken too seriously. Chiang Kai-shek's claim to American diplomatic recognition depended on the contention that his government was a legitimate government of all China and only temporarily stationed in Taiwan. Conservatives often sensed that US support for Taiwan would be weakened, if Americans came to believe the Nationalists were a minority dictatorship.
Now, liberals such as Sen. Edward Kennedy (D) of Massachusetts, who has long been concerned about allegations of human-rights abuse in Taiwan, may no longer have a monopoly on the issue of the native Taiwanese.
Conservatives who favor continued American ties with Taiwan may begin to enlarge their definition of Taiwan's people to include those who oppose Nationalist rule, as well as those who support it.