Washington — The Democrats seem to be acquiring the hang of it. Chicago's blacks registered in great numbers and went to the polls, and now the party appears to be on the verge of electing that city's first black mayor.
But Chicago is only one example of what Democrats would like to do nationwide - among blacks, Hispanics, and other low-income groups. Most of the people in those groups call themselves Democrats, but for years they have been in the ''seldom vote'' category.
Lloyd Bentsen, chairman of the Democratic Senatorial Campaign Committee, points to the 1982 election in Texas as another illustration of how the Democrats, ''through the use of modern campaign mechanics,'' can get out the minority vote and win.
''In Texas,'' said Senator Bentsen over breakfast the other morning, ''we increased the voter turnout higher than any other state between 1978 and 1982. And it rained in all the traditional Democratic areas in Texas on election day.''
He paused, then continued: ''But every time I called into those areas the answer would be, 'but they are standing in the rain' - and how those Democrats turned out! We had made 2.2 million phone calls during the campaign. And we made a million phone calls on election day.
''We made so many phone calls that when the polls closed at 7 o'clock over most of Texas and we turned those phone lines into El Paso (in the West), a woman finally said, 'Yes, I'm going to vote - if the Democrats will quit ringing this phone so I can vote.' ''
Senator Bentsen, who will help shape the national Democratic strategy in 1984 , is convinced that the techniques used in Chicago - and in Texas - are transferable everywhere.
''We won absentee ballots, too,'' he said of the Texas election. ''When before did Democrats ever win absentee ballots? That's traditionally a Republican vote. But we did a job on registration. And we did a job on getting our vote out. And we can do this all over the country in 1984.''
The senator was responding, in part, to this question: ''Blacks and Hispanics never voted for Reagan in the first place, so why should he be so concerned if they aren't behind him today?''
''You say 'never voted for Reagan,' '' said Bentsen. ''True. But a lot of them never voted before. For anybody. And we really turned them out in Texas. And they voted. And I will tell you who responds more to modern campaigning methods than anyone else: That's this Democratic constituency that hasn't voted before.''
Here Bentsen emphasized what he sees as the Democratic Party's greatest advantage when it goes all out to get the poor registered and to the polls: ''You know, the Republicans have done a superb job with phone banks. And with voter registration. And getting out their vote.
''But their vote traditionally gets out anyway. So it is very marginal what they improve. But that's not true on the Democratic side. You have a great many Democrats that just don't vote. And we have proved in Texas what you can do when you put modern political mechanics to work. And we can and will do that everywhere in 1984.''
Bentsen concedes that there must be some reason for blacks and Hispanics to get out and vote. An improving economy might give them less of an incentive to get involved in the election process, he admits.
''But,'' he said, ''I think in 1984 you will still have the high unemployment that will be a deep concern to the poorer people. And they will have this feeling that the Republicans have not been fair to them.
''So I think you are going to see the kind of response we saw in Texas all over the United States and a response to a degree never seen before, because of the modern mechanics of getting out the vote used by the Democrats and the registration job done by the Democrats.''