Philadelphia ? The Democratic Party is approaching the 2004 elections in its weakest position since Franklin Roosevelt forged the enduring Democratic coalition 70 years ago, a prominent pollster warned Monday.

The party still has solid support from the core of Roosevelt’s coalition — union members, minorities and the working poor — pollster Mark Penn said. It also enjoys solid support from gays and Hispanics, the nation’s fastest-growing minority.

But less than one-third of Americans now consider themselves Democrats, down from 49 percent at their peak in 1958. And Democrats lag well behind Republicans among other growing groups of voters whose loyalties swing back and forth between parties and who hold the key to close elections — including suburbanites, professionals and middle-class families with children. That leaves the party in a poor position to build the new coalition it needs to beat President Bush and build an enduring majority in an evenly divided country.

“In terms of the percentage of voters who identify themselves as Democrats, the Democratic Party is currently in its weakest position since the dawn of the New Deal,” Penn told a gathering of the Democratic Leadership Council, a group of centrist Democrats. “Exciting the Democratic base alone will not bring enough voters into the Democratic fold.”

One key problem, Penn and others said, is that Democrats are perceived as catering to a political base that is losing its electoral clout in a changing country.

The Penn poll of 1,225 likely 2004 voters was conducted June 29-July 1 and had a margin of error of plus or minus 2.8 percentage points.

Democratic presidential candidate Sen. John Kerry, D-Mass., speaks during an education forum at the Elks Club in Sioux City, Iowa. Pollster Mark Penn warned Monday that Democrats were approaching the 2004 elections in the worst shape in 70 years.