WASHINGTON (By Janet Hook, LATimes) March 23, 2007 — Public allegiance to the Republican Party has plunged during George W. Bush's presidency, as attitudes have edged away from some of the conservative values that fueled GOP political victories, a major survey has found.

The survey, by the nonpartisan Pew Research Center for the People & the Press, found a "dramatic shift" in political party identification since 2002, when Republicans and Democrats were at rough parity. Now, 50% of those surveyed identified with or leaned toward Democrats, whereas 35% aligned with Republicans.

What's more, the survey found, public attitudes are drifting toward Democrats' values: Support for government aid to the disadvantaged has grown since the mid-1990s, skepticism about the use of military force has increased and support for traditional family values has decreased.

The findings suggest that the challenges for the GOP reach beyond the unpopularity of the war in Iraq and Bush.

"Iraq has played a large part; the pushback on the Republican Party has to do with Bush, but there are other things going on here that Republicans will have to contend with," said Andrew Kohut, director of the Pew Center. "There is a difference in the landscape."

A key question is whether the trends signal a broad and lasting change in the balance of power between the national parties or a mood swing that will pass or moderate. It remains to be seen whether Democrats can capitalize on Republican weaknesses and achieve durable political dominance.

"This is the beginning of a Democratic opportunity," said Illinois Rep. Rahm Emanuel, chairman of the House Democratic Caucus. "The question is whether we blow it or not."

Whit Ayres, a Republican pollster, said he believed the Pew poll exaggerated his party's problems and that the situation would improve as attention shifted to choosing the GOP's 2008 presidential nominee.

At that point, "we will have a far more level playing field than we have today," Ayres said.

But other Republicans fear the poll signals a clear end to an era of GOP successes that began with President Reagan's election in 1980, saw the party take control of Capitol Hill in 1994 and helped elect Bush twice.

"There are cycles in history where one party or one movement ascends for a while and then it sows the seeds of its own self-destruction," said Bruce Bartlett, a conservative analyst and author of the 2006 book "Impostor: How George W. Bush Bankrupted America and Betrayed the Reagan Legacy."

Bartlett added, "It's clear we have come to an end of a Republican conservative era."

The Pew poll measured the views of 2,007 adults from Dec. 12 through Jan. 9. It has a margin of error of plus or minus 2.5 percentage points.

The current gap between Republican and Democratic identification — which Pew measured by counting people who said they leaned toward a party as well as those with firm allegiances — is the widest since the group began collecting data on party allegiance in 1990.

As recently as 2002, the two parties were tied, with each drawing support from 43% of those surveyed. But Democrats have gained an advantage over Republicans almost every year since.

Kohut said the spread between the parties mostly reflected the defection of independents from the GOP more than a more favorable assessment of the Democrats.

The survey found that the proportion of those expressing a positive view of Democrats has declined since January 2001 — when Bush took office — by 6 percentage points, to 54%. But the public's regard for Republicans has cratered during the Bush years, with the proportion holding a favorable view of the GOP dropping 15 points, to 41%.

Although Republicans rode to political power calling for smaller government, support for government action to help the disadvantaged has risen since the GOP took control of Congress in 1994. At that point, a Pew survey found that 57% said the government had a responsibility to take care of people who could not take care of themselves; now, 69% said they believed that.

On the other hand, support for Bush's signature issue — a strong, proactive military posture — has waned since 2002, when 62% said that the best way to ensure peace was through military strength. In the recent poll, 49% said they believed that.

On social issues, the survey found that support for some key conservative positions was on the decline. For instance, those who said they supported "old fashioned values about family and marriage" dipped from 84% in 1994 to 76% in the recent survey.