Tokyo ? Keiko Saito’s son-in-law recently lost his job and can’t find another. As she and her husband approach retirement, they worry whether their pensions are safe. The economy seems chronically incapable of recapturing its glory days.

For decades, 58-year-old Saito supported the Liberal Democrats, a party synonymous with Japan’s rise, its fantastic growth and its postwar peace.

Now she is angry, ready for change and looking very typical. Polls indicate a strong possibility that elections Saturday will end the Liberal Democrats’ 54 years of nearly uninterrupted rule, one of the most successful runs by a political party in the noncommunist world.

The party’s demise has been forecast before, and it has usually confounded its doomsayers. But this time, analysts say, it’s different. A long-brewing public uneasiness has changed to a feeling of being downright threatened. The forces that underpinned the Liberal Democrats’ grip on power are not what they once were.

And for the first time, the Liberal Democrats have a credible rival in the Democratic Party of Japan, which promises to put more money in consumers’ pockets, cut wasteful spending and restore Japan’s prestige as the world’s second-largest economy.

“I have two grandchildren and I’m really worried about their future,” said Saito. “The Liberal Democrats seem to be only obsessed with holding onto power for its own sake, and I’m afraid they are not seriously thinking about the nation.”

Even though the Democratic Party has borrowed the theme of change from U.S. President Barack Obama’s election campaign, it could prove a challenge for the White House if the party wins the premiership. The party promises a more independent stand in world affairs, in contrast to the Liberal Democrats who were always Washington’s most dependable major ally.

The Democrats have already established their clout by taking control of the upper house of parliament in 2007. Saturday’s election is for the more powerful lower house, which chooses the prime minister.

The Liberal Democrats have 302 seats in the 480-seat lower house, the Democratic Party just 112. But several polls published last week by major newspapers say the Democrats could win 300 seats. In a sounding by the Asahi, a major center-left daily, the ruling party had 21 percent, the Democratic Party 40 percent. Undecided voters, which the Asahi put at 27 percent, will be a major factor, and turnout is expected to be extremely high.

“Voters used to seek stability and were afraid of a leadership change,” said Koichi Nakano, a political science professor at Tokyo’s Sophia University. “But they have realized this country won’t get anywhere if they don’t get rid of the Liberal Democrats, who are no longer capable of providing strong leaders or consistent policies.”