The U.S. Democratic Party's presidential contenders are making a final push to win over undecided voters Monday before primary elections and caucuses in seven states.

Public opinion polls show the current front-runner for the Democratic Party's nomination, Massachusetts Senator John Kerry, is either leading or near the lead in all seven states. However, some surveys indicate that as many as 20 percent of those who intend to vote Tuesday have not yet decided whom to support.

Despite Mr. Kerry's prominence in the polls, Tuesday's contests, scattered across the country, could produce several different winners. Seven candidates are still campaigning to be their party's choice to oppose President Bush in November's presidential election.

Primary elections will be held Tuesday in Missouri, South Carolina, Delaware, Arizona and Oklahoma; and Democrats in New Mexico and North Dakota will meet in caucuses to choose their favored candidate. Those who do not fare well in any of the seven states will face increasing pressure to drop out of the race.

In South Carolina, a late poll shows North Carolina Senator John Edwards with a one percentage point lead over Mr. Kerry. Senator Edwards says he must win in South Carolina if he is to stay in the Democratic race. Political experts say Senator Kerry can afford to come in second in South Carolina and still maintain his overall lead.

The battle for second place in Tuesday's overall voting remains a toss-up between Senator Edwards and retired General Wesley Clark.

Howard Dean, the former Vermont governor who was the early front-runner before Senator Kerry's recent advances in the Iowa caucus and the New Hampshire primary, is not campaigning actively in the seven states voting Tuesday, but in other states where voting will take place later.

The Democrats' national chairman, Terry McAuliffe, says he expects the party will not have a definite choice for its presidential candidate until at least mid-March, after primaries and caucuses in 35 more states.

In a television appearance Sunday on NBC's Meet the Press, Mr. Dean said he would step aside if another candidate wins enough delegates to clinch the Democratic nomination at this summer's party convention.

The seven active Democratic candidates are Senator Kerry, Senator Edwards, General Clark, Mr. Dean, Senator Joseph Lieberman of Connecticut, civil-rights activist Al Sharpton and Ohio Congressman Dennis Kucinich.

Some information for this report provided by Reuters, AFP and AP.