Has "Nick-pac" had it?

That question is unlikely, perhaps, when the National Conservative Political Action Committee (NCPAC) is on its way to raising a record $9 million to $10 million for the 1982 elections, giving it a bankroll nearly as big as that of the Democratic National Committee. But the question does keep coming up.

Single-handedly, NCPAC introduced a maverick element into electoral politics in 1980. It used money raised from sophisticated direct mail fund-raising techniques to wade into campaigns on its own -- rather than on behalf of a particular candidate -- and run negative ads against liberal targets.

Its efforts are generally credited with helping to knock off Sens. George McGovern, John Culver, Birch Bayh and Frank Church. For a season, NCPAC was all the rage.

Seasons change. Consider:

* Flush from its big victories in 1980, NCPAC initially announced that it would go after 21 more liberal senators this year. That number has dwindled to seven, and most political strategists consider only one or two of these targets vulnerable.

* In many states, the targets of the NCPAC attacks have been helped at least as much as they have been hurt. In Maryland, for example, Sen. Paul S. Sarbanes' political "negatives" have been raised by NCPAC's $600,000-plus ad campaign, but he also has been able to use his hit-list status to raise money and transform his image from that of indifferent campaigner to fighter.

* Persistent doubts about the credibility of NCPAC ads have caused several television stations to keep them off the air. NCPAC has sued, alleging a conspiracy between the media and liberal politicians, and the case is in federal court.

* Perhaps most important, NCPAC targets have learned how to counterpunch.

Last time out, many Democrats chose to ignore the attacks. Now they take them head on, usually in ads of their own, and focus on alleged smear tactics of an outside group. Increasingly, the targets also have started to wrap NCPAC's tactics around their opponents' necks.

"Politicians have learned that you can't leave them alone," said George Christian, press secretary to President Johnson and now a political consultant in Austin. "You have to call them liars and prove it."

That was the strategy of Sen. Howard W. Cannon (D-Nev.), target of a $130,000 NCPAC media effort. Many credit it with helping him defeat Rep. James D. Santini (D-Nev.) by more than 5,000 votes in their hard-fought Senate primary race last Tuesday.

When NCPAC ads began attacking Cannon for his Panama Canal treaty vote, for allegedly having a poor Senate attendance record and for allegedly voting for a congressional pay raise, the Cannon camp put prominent Nevada Democrats on the air to swing back at NCPAC.

Cannon meanwhile, sought in his campaign speeches to tie NCPAC to Santini. He pointed out that the attendance record was for a year he was busy campaigning and that the pay-raise vote was on a procedural matter, not a substantive one.

Santini said he thinks it was he who came out on the short end. "The NCPAC issue was detrimental to the Santini campaign," he said. "It clouded the other issues."

From Texas comes polling data suggesting that NCPAC's sword is not only two-edged, but also that the backside is sometimes sharper. When the conservative group ran a series of TV ads attacking Sen. Lloyd Bentsen (D-Tex.) in the Lubbock area last summer, Bentsen, too, fired back with ads of his own.

Polling done by Shipley & Associates of Austin showed that 47.5 percent of a random sample said they thought the NCPAC ads were unfair, and that only 17.5 percent said they thought they were fair.

Moreover, 37.7 percent said they thought Bentsen's opponent, Rep. James M. Collins (R-Tex.), was responsible for the ads, compared with 24.2 percent who said they thought he wasn't.

The Bentsen counterattack ad ran this way: "During the next few weeks, you're going to see some distasteful television commercials by some Washington promoters specializing in lies and half-truths. NCPAC has joined James Collins in an attack on Sen. Lloyd Bentsen. NCPAC is the same organization that said it could elect Mickey Mouse, that bragged that NCPAC could lie through its teeth and the candidate it helps stays clean. So when you see those ads, remember, NCPAC and James Collins are not trying to build, they're trying to destroy."

Democratic strategists say the success of these counterattacks spells the beginning of the end for NCPAC.

"They have played so fast and loose they've destroyed their own credibility," said Eugene Eidenberg, executive director of the Democratic National Committee. "The common sense of the American people rejects them."

Not everyone is so sure. Democratic campaign consultant Victor Kamber, who organized the Progressive Political Action Committee, (PROPAC) to do to conservatives what NCPAC does to liberals, said it is "ludicrous to think that NCPAC is dead."

He said that from the start NCPAC wouldn't have as successful a year as 1980 because there simply aren't as many vulnerable liberal incumbents.

"But any group that has can raise $9 million or $10 million and is prepared to throw hundreds of thousands of dollars into a race is going to have an impact," he said.

He cited recent research by pollster Lance Tarrance & Associates of Houston, suggesting that voter resentment of NCPAC already had set in during the 1980 campaign.

Tarrance found that 78 percent of the voters in South Dakota at the end of the 1980 campaign knew what NCPAC was, and that fully two-thirds of that group had an unfavorable impression.

Still, he also found that a high percentage of the vote in that race, 28, was "against McGovern rather than for his opponent." His conclusion is that there is strong suggestive evidence that the NCPAC's ads were a bit like the Charmin television commercial: people may not like them, but they buy the product.

Tarrance said he believes that negative advertising by independent groups is here to stay. As for NCPAC, the group says it has no plans to fold its tent.

Joseph Steffen, a NCPAC spokesman, said last week that it is still far too early to call the Cannon race in Nevada a defeat.

"The object wasn't to elect Santini," he said. "It was to beat Howard Cannon. We think we have softened him up for the fall."