The two major candidates in South Dakota's Senate race are spending millions to win over thousands of voters, mirroring the continued closeness of many key congressional races after months of heavy spending.

Republican and Democratic party strategists are closely examining new campaign finance reports the candidates are filing with the Federal Election Commission this week, looking for those who might need their help down the stretch.

The candidates and the parties are unleashing their final volleys in a multimillion-dollar effort to sway voters who will determine control of Congress on Nov. 5.

Asked if trying to reach those who remain uncommitted after weeks of television, radio, direct mail, door-to-door and other campaign efforts becomes a waste of money at some point, Democratic Party Chairman Terry McAuliffe had an emphatic response.

"God, no, we don't write the undecideds off,'' McAuliffe exclaimed.

In South Dakota's Senate race, for example, the race between Democratic incumbent Tim Johnson and Republican Rep. John Thune may come down to fewer than 1,000 votes, McAuliffe and other political strategists predict. Polls show that roughly 35,000 voters, at most, have yet to make up their minds.

Johnson has spent at least $6 million so far on the campaign, compared with about $4.6 million for Thune, campaign finance reports released Tuesday show. Thune had about $317,574 on hand as October began, compared to $214,816 for Johnson.

Explaining Johnson's level of ready cash, campaign spokesman Dan Pfeiffer said Johnson spent a substantial sum last spring locking up all the TV ad time he thought he would need, anticipating an ad blitz amid the state's campaigns for Senate, governor and an at-large House seat. Thune and Johnson — each starting with more than 90 percent name recognition among voters — began airing ads last winter.

In Georgia's Senate race, Republican Rep. Saxby Chambliss is counting on $900,000 in ads by the National Republican Senatorial Committee from Labor Day through the election to help chip away at Democratic Sen. Max Cleland's roughly 3-to-1 spending advantage.

Cleland has raised and spent more than $8.7 million, compared with about $5 million in fund-raising and $3 million in spending by Chambliss, according to campaign reports released Tuesday. Chambliss started the month with more cash on hand: $1.7 million, compared to $203,085 for Cleland.

"It's a very big boost to get that little extra bit,'' Michelle Hitt, a spokeswoman for the Chambliss campaign, said.

Republican Elizabeth Dole has spent more than $10 million trying to land North Carolina's open Senate seat, starting the month with $592,147 on hand.

That compares to $1.1 million on hand for Democrat Erskine Bowles, who spent $7 million as of Sept. 30. Though Bowles reported more ready cash, he also reported more campaign debt: nearly $3 million, compared to $168,773 for Dole.

Among other hot races:

— Minnesota Democratic Sen. Paul Wellstone had outspent his Republican challenger, former St. Paul Mayor Norm Coleman, by nearly $3 million as of September's end.

— Missouri Democratic Sen. Jean Carnahan reported spending twice as much as Republican challenger Jim Talent. Carnahan began October with $1.1 million on hand, compared with $2.8 million for Talent.

— In New Hampshire's Senate race, Democratic Gov. Jeanne Shaheen reported spending $2.7 million, with $1.3 million on hand. Republican Rep. John Sununu reported $1.7 million in spending and $297,622 on hand.

— In a costly incumbent-vs.-incumbent House matchup, Connecticut Republican Rep. Nancy Johnson reported spending more than $2.4 million so far this election, compared to more than $1.6 million for Democratic Rep. Jim Maloney.

— In a Pennsylvania incumbent contest, Democratic Rep. Tim Holden reported $792,140 in spending and $574,533 on hand, while Republican Rep. George Gekas reported spending about $500,000, with $486,085 on hand.

The GOP and Democratic national committees are also releasing new totals.

The Democratic National Committee has raised $110 million for the 2002 election, beating its previous midterm election record, set in 1998, by $28 million, McAuliffe said. The committee had $15 million on hand as of Sept. 30.

The Republican National Committee has collected at least $184.5 million, also a new midterm record, and reports $30.7 million on hand.