In 1988, George H.W. Bush warned voters his Democratic opponent represented the "failed liberal policies of the past." Liberal-bashing worked wonders, carrying the elder Bush from a 12-point deficit in polls in early July to a 10-point victory over Michael S. Dukakis on Election Day.

In 1996, the same strategy fell flat. "Liberal, liberal, liberal Bill Clinton," brayed Republican nominee Robert J. Dole about the incumbent, a line that hardly hindered Clinton's leisurely stroll to reelection.

This year's presidential campaign marks the latest effort to hurl the L-word -- the most familiar and, on some occasions, most lethal spear in the Republican arsenal. President Bush's campaign spokesmen have called the Democratic ticket of Sen. John F. Kerry (Mass.) and Sen. John Edwards (N.C.) the most liberal ticket in U.S. history.

The notion that the Democratic ticket is on the left by historical standards is implausible, say Kerry defenders, noting that in his Senate career the nominee has voted for major deficit-reduction measures sponsored by avowed conservatives. He also voted for landmark 1996 legislation that imposed time limits and work requirements on welfare recipients, legislation that prompted outraged opposition from many liberals. His presidential campaign platform includes tax increases for the rich, tax cuts and credits for middle-class earners, and an increase in the size of the armed forces.

Republicans invoke independent sources to back their charge. The National Journal, a Washington nonpartisan policy magazine, and Americans for Democratic Action, a liberal advocacy group, have produced vote analyses that last year placed Kerry and Edwards at the liberal end of the Democratic spectrum in the Senate. But even these organizations warn that their liberalism indexes can, for a variety of reasons, create misleading impressions.

The significance of this crossfire over the Democratic ticket's ideological profile remains uncertain. Several Democratic strategists say Kerry is wise to resist being tattooed as liberal, since only about 20 percent of national voters identify themselves this way, and the word evokes negative associations with big government and cultural elitism for many of the rest.

At the same time, Democratic strategists say the word by itself lacks the potency it had. Kerry needs "to be attentive to specific issues, but in general the label just doesn't have the same explosive power," said Stan Greenberg, a Democratic pollster who has studied how cultural liberalism produced a flight of white lower-middle-class voters from the Democratic Party in the 1980s.

"There's no evidence in the data I'm looking at that [Kerry and Edwards] are being hurt by it," Greenberg said. The liberalism charge once was an effective "wedge issue" to scare independent voters away from Democrats, he said, but now it works mainly as a "base strategy" to motivate people who already lean Republican but need a reason to get to the polls.

Whether brandishing the liberal stick works as politics, the question lingers: Is it true?

National Journal's annual analysis of legislators' votes found in 2003 that Kerry and Edwards, respectively, had the first- and fourth-most-liberal voting records in the Senate. In assigning the rankings, editors identified 63 important votes in the Senate last year and applied a complex statistical formula designed to illuminate how a legislator's record followed an ideological pattern.

Despite the aura of scientific precision, in individual years the results can sometimes be thrown off kilter in ways that leave a distorted impression.

In a recent issue, the magazine noted that Kerry and Edwards, busy campaigning, were absent from the Senate for many of the votes that went into the latest index, so only certain votes entered the formula. Although Kerry has scored consistently on the liberal end of the journal's index since coming to the Senate in 1985, 10 current senators have a higher lifetime average, the magazine said. Edwards, just finishing his first term, has a lifetime score that "puts him in the moderate wing of his party."

Americans for Democratic Action, or ADA, which wants senators to earn a high rating, has a more straightforward ranking system. Each year the group identifies 20 important votes and assigns five points each time a senator votes the way ADA advocates. Kerry has a lifetime average of 92. As Republicans note, this is two points higher than Democrat Walter F. Mondale's lifetime ADA average. Mondale, the 1984 presidential nominee, is regarded as the most emphatic old-style liberal offered by Democrats in recent decades.

But such numerical comparisons do not reflect the historical context in which the rankings are made. During the 1970s, when Mondale was casting Senate votes, Democrats controlled Congress. Many Democrats routinely backed dramatic expansions of government's role, such as national government-run health insurance or federal jobs programs to guarantee full employment, that go far beyond anything a Democratic nominee has supported in recent years. On the other hand, there are issues today, such as support for gay rights, that even ardent liberals of 30 years ago would not have gone near.

One of Kerry's more effective defenses against the charge that he is a reflexive liberal may be the support of the centrist Democratic Leadership Council, or DLC. Formed in 1985 out of concern that the party had drifted too far left, the group has rarely hesitated to criticize Democrats who it believes cleave to an outdated special-interest brand of liberalism. The DLC, which criticized former Vermont governor Howard Dean's candidacy in last winter's primaries, has been enthusiastic all year about Edwards and Kerry.

Al From, the group's founder, said the Republican accusations of liberalism "pretend that the reform movement of the 1990s" in the Democratic Party under President Bill Clinton never happened. From maintains that, by backing anti-crime measures and welfare reform over the objections of many urban liberals and by backing free-trade measures over the objections of labor unions, "Kerry was here and was an important part of the redefinition of the party."

Mark J. Penn, Clinton's pollster, maintains that the liberalism charge is still dangerous for Democrats, who he says should move aggressively to rebut the accusation. The liberal label is dynamite, he said, because for many of the 80 percent of the electorate who do not identify themselves as liberals, the word is synonymous with high taxation and naive dovishness on national security. But he said the dynamite cannot explode if most voters do not believe it is real.

"You still don't want to be perceived as 'liberal,' " he said, "any more than you want to be perceived as 'right wing.' " In this year's race, he said, Bush is carrying the greater ideological burden. Rankings such as the National Journal's do not cause problems for Kerry so long as "you don't have a real-time event that depicts him as a liberal."

Scott Stanzel, a Bush-Cheney spokesman, said the campaign does have such real-time evidence of Kerry's leanings, including his vote against an $87 billion spending measure to support military operations in Iraq. Kerry said he would have backed the spending if the administration had agreed to pay for it by rescinding some of its tax cuts for the wealthy. Kerry also is opposed to the death penalty, which most Americans support. Stanzel said Kerry has "the pattern and record of someone who is out of the mainstream."

Kerry was helped on his way to the nomination by, for the most part, avoiding ideological battles within his party. Polling showed that moderates and liberals backed Kerry as the most likely to beat Bush.

In addition, as Congress has become more polarized on partisan grounds, the whole notion of distinct ideological wings within each party has become less relevant than the daily warfare between the parties, said ADA communications director Don Kusler.

This is reflected in the group's liberalism ratings. As recently as 1980, for example, the ADA average for all Democratic House members was 58 percent, as legislators often crossed lines and backed bipartisan measures. Last year, the House Democratic ADA average was nearly 90 percent. Similar, though slightly less pronounced, trends have occurred in the Senate, also riven by nearly constant partisanship.

Kusler said this trend is one reason that comparison of Kerry's rating with Mondale's is not particularly apt.

For his part, Kusler wishes that a word that he regards as having an honorable heritage -- backing civil rights at home and robust human rights policies abroad -- will be one Democratic presidential nominees will again embrace.

Conservatives have "been working on redefining the word 'liberal' for decades, and turning it into a four-letter word," Kusler said. "We don't want to give up the word. We've been losing the fight for the definition."

Walter F. Mondale, the 1984 presidential nominee, is considered an emblematic old-style liberal.