When it comes to November battlegrounds, the maps conflict.

Contests in roughly a dozen states are likely to decide party control of the Senate this fall. Meanwhile, the campaigns of President Bush and his Democratic challenger, Sen. John F. Kerry (Mass.), are pouring millions of dollars into television ads in about 20 states.

The two fights are taking place largely in separate worlds. Of the 20 battleground presidential states, five have no Senate races this year. In eight others, one party is a clear favorite.

Looked at the other way, of the top 12 Senate races, half or fewer are unfolding in states that are drawing major attention from the presidential rivals.

In a call with reporters last week, Sen. Jon S. Corzine (N.J.), chairman of the Democratic Senatorial Campaign Committee, was brimming with confidence. "The momentum and movement continue in our direction," he said. "If we went to the polls next Tuesday, we would take back the Senate." But he added a caveat: "We have less overlap than I would like" between the states Kerry is targeting and those where crucial Senate races are on tap.

The flip side of Corzine's regret was expressed by Bush campaign manager Ken Mehlman. "The Senate battlegrounds are places where John Kerry Democrats are not likely to win. In those states, candidates will have to decide whether they are with Kerry or with the folks at home," he said.

At a time when race-by-race prospects for Democrats have improved enough that some neutral observers are beginning to say the GOP's 51 to 48 majority might be overturned, the expected Bush strength in most of the states where Senate seats are up for grabs looms as a major barrier to Democratic prospects.

Dan Allen, spokesman for the National Republican Senatorial Committee, said that of 10 states he would rate as closest, "nine are very good for Bush." Those states include South Dakota, where Senate Minority Leader Thomas A. Daschle faces a strong challenge, and five southern states -- Florida, Georgia, North Carolina, South Carolina and Louisiana -- where incumbent Democrats are retiring.

Three states where Republicans must defend seats that could be in jeopardy -- Alaska, Colorado and Oklahoma -- also lean to Bush. Among Allen's top 10, only Illinois, where the retirement of Sen. Peter Fitzgerald (R) opens a seat, was carried in 2000 by Al Gore.

Some Democrats still question who really won Florida, but Bush's 2000 margins in the other eight states ranged from 6 percentage points in Arizona and 8 in Louisiana up to 22 points in Oklahoma and South Dakota and 31 points in Alaska.

Republicans add Washington to their list of targeted Senate races, and Democrats include Pennsylvania. Both those states went to Gore, but the overall tilt of the playing field remains with the GOP.

Still, the Kerry campaign and the Democratic Party are laying plans for "coordinated campaigns" in several of the states where important Senate races are unfolding. Planning for those cooperative efforts -- in which presidential, senatorial and other candidates jointly finance and cooperatively staff voter registration and turnout operations and attempt to reinforce one another's messages -- was delayed by Kerry's preoccupation with fundraising and preparation of his television spots in March and April.

A more delicate dance is being performed by Kerry and individual Senate candidates, depending on circumstances in particular states. Rep. Joseph M. Hoeffel III (D), challenging Sen. Arlen Specter (R) in Pennsylvania, has been at Kerry's side almost every time the presidential candidate has been in the state, where Kerry is a slight favorite to repeat Gore's victory. Even in Colorado, where Kerry is not the favorite, Senate candidate Ken Salazar (D) met with the Massachusetts senator to discuss how they can help each other.

In an interview, Corzine cited Salazar, who has carried Colorado as attorney general, and state Sen. Barack Obama, the Democratic nominee in Illinois, as examples of Senate candidates who may provide "reverse coattails" for Kerry. Former White House chief of staff Erskine Bowles in North Carolina and Rep. Chris John in Louisiana could also improve Kerry's long-shot chances of victory in those states.

"I don't know of a single state where the Senate candidates are running away from Kerry," said his deputy campaign manager, Steve Elmendorf.

On the other hand, not all the Senate aspirants whose potential has excited Democrats are rushing to embrace Kerry or his policies. In South Carolina, a state Bush carried by 16 points, Senate challenger Inez Tenenbaum has led the ticket in her races for superintendent of public instruction, and Republicans face a primary and runoff before they will know her opponent. But as she tries to replace retiring Sen. Ernest F. Hollings (D), Tenenbaum has lined up with Bush -- not Kerry -- in supporting the death penalty, a ban on some late-term abortions and a constitutional amendment to outlaw same-sex marriages.

In the headlined race against Daschle, former representative John Thune (R) has tried repeatedly to link the Democratic Senate leader to Kerry's liberal or controversial policies, even unearthing a newspaper story from 1996 quoting Kerry as saying he favored steps to "get rid of the Agriculture Department, or at least render it three-quarters the size it is today."

Corzine said he is concerned that in states such as South Carolina, South Dakota, Georgia and Alaska, it is unlikely that the Kerry campaign, the Democratic National Committee or independent groups supporting Kerry will allocate money and manpower to build a turnout that could help Senate candidates.

On the GOP side, Mehlman and Allen insist that even if such states appear certain to support Bush, the presidential campaign will provide a favorable environment for Senate candidates. Allen said that Bush "had a huge effect in 2002," when his campaigning for GOP Senate and House candidates boosted turnout in Republican areas. "He can do that again this year, even if he doesn't go there," Allen said, pointing out that recorded phone calls with Bush's voice, TV spots and mailings can help down-ballot candidates.

Since an early appearance for Sen. Christopher S. Bond (R-Mo.), Bush has been rather sparing in fundraising for Senate candidates. But Mehlman said the president, Vice President Cheney and other senior administration officials have logged 46 fundraisers for Senate candidates as of last week. He added that "our donors are being encouraged to support the joint candidate committees" in states with Senate battles -- the GOP equivalent of the Democrats' coordinated campaigns.

One presidential fundraiser that drew attention was a stop in Pittsburgh to aid Specter before last month's GOP primary, in which Specter barely defeated Rep. Pat Toomey (R). Conservative groups such as the Club for Growth backed Toomey against the more moderate Specter, and some conservatives were unhappy that Bush intervened and -- in their view -- provided Specter's margin of victory.

The White House also has caught flak from some conservatives for backing former housing and urban development secretary Mel R. Martinez against Bill McCollum, the former House member who was previously favored in the primary for the open Senate seat in Florida. And in Alaska, appointed Sen. Lisa Murkowski -- beneficiary of a Cheney fundraiser -- has been forced to defend her Bush credentials against the claims of a more conservative opponent.

But whoever wins some of these intraparty fights, Mehlman said, "the president is very committed to avoiding a lonely victory, so we are working closely with the state parties and our candidates."

Corzine conceded that "the layout of the presidential map is not the most comfortable for us -- with five Senate seats to defend in the South -- and targets for us in Colorado, Oklahoma and Alaska." But he suggested that Republicans may be disappointed in their hopes for presidential coattails. "As more and more people decide the country is off on the wrong path, I think they are discovering the advantages of checks and balances," Corzine said. "That's what Senate Democrats can provide."

Political researcher Brian Faler contributed to this report.