Washington — Sen. Alan K. Simpson saw the door slam on immigration reform during the closing weeks of this year's Congress. But the Republican, who is leading the reform effort although his own state of Wyoming is nowhere near the United States borders, kept knocking.
And late last month, the door cracked open again. House Speaker Thomas P. O'Neill Jr. (D) of Massachusetts said he would put the legislation on the House floor early in the new session that begins Jan. 23. Only a few weeks before, the speaker had pulled the bill off the 1983 schedule and announced there was ''no constituency'' for immigration reform.
Notables including Presidents Jimmy Carter and Gerald Ford and the Rev. Theodore Hesburgh, president of Notre Dame University and a longtime civil rights advocate, telegrammed their support for the bill, charging that ''America's immigration policies are in a shambles.''
But what finally moved Mr. O'Neill, says aide Ariel Weiss, was ''a more careful review of the provisions'' of the legislation, which has already passed the Senate, and Senator Simpson's assurances that Republicans would not use the issue for partisan politics.
The Wyoming senator had vowed to convince O'Neill that he was not setting a trap for Democrats, even if it meant going to the speaker's Massachusetts home and waiting on his porch. As it turned out, the two met in secret in O'Neill's Washington office on Oct. 25.
A major item for their talk was a rumor that President Reagan would veto the bill to win favor for Republicans among Hispanics who dislike it. Simpson tried to lay that theory to rest.
''I said, 'You don't know me, Tip, if you think that I spend time in partisanship here,' '' recalls Simpson in an interview. The GOP senator said that a veto had never been mentioned except concerning an amendment to provide $ 11 billion in aid to immigrants.
Then Simpson pledged to take the House-Senate proposal to the White House and guarantee the President's signature before the House takes a final vote.
Party politics has never played a role, according to Simpson, who was appointed to a bipartisan commission to study the problem of illegal immigrants soon after arriving in Congress in 1979. He has teamed up with a Democrat, Rep. Romano L. Mazzoli of Kentucky, to push for legislation that would legalize many longtime resident aliens while enacting sanctions against employers who knowingly hire undocumented foreigners.
Simpson says that the only talk of partisan politics came from a group of unnamed GOP officials who visited him about a year ago urging him to drop the reform bill. ''They said, 'Don't you realize that if legalization comes (for illegal aliens) probably a great number of them will register Democratic?' '' Simpson says. ''I said, 'I don't give a whit. It's a grievous national problem that we've got to get off our backs.' ''
He points to polls that show up to 90 percent of Americans and 70 percent of Hispanics want immigration reform. But despite those figures, there has been no outpouring of public support for reform on Capitol Hill.
''How do you get mail out of people who have been sitting there for 30 years watching nothing get done?'' asks Simpson, but he also attributes the public silence to ''an ugliness.'' ''You know, I will be somewhere in the United States and somebody will say, 'Are you this guy Simpson? . . . Are you the guy who's going to take all the Vietnamese out of my laundry? Are you the guy who's going to ruin my business so that the bank will take my walnut farm?' ''
Simpson says that he and Mazzoli have found that sentiment ''bubbling along underneath'' the immigration reform issue. ''It's called exploitation. . . .''
The senator says he's heartened by the fact that O'Neill made public his promise to bring up the reform bill, which has been consistently opposed by Hispanic members of Congress. But the Simpson-Mazzoli bill is far from a shoo-in.
Hispanic lobbying groups and the congressional Hispanic Caucus firmly oppose it and are drawing up an alternative, a five-year plan of immigration reform which would include tighter border enforcement but no employer sanctions. Penalties for hiring illegal aliens would lead to job discrimination against anyone who looks foreign, charge Hispanic groups.
''Hispanics want reform, but they do not want Simpson-Mazzoli.'' says Arnold Torres, chief lobbyist for the League of United Latin American Citizens.