Republicans and Democrats agree on one thing: Victory in Tuesday's elections will reflect the nation's mood and could signal how much success President Bush will have in his re-election campaign next November.

"If the Democrats win, you can be sure the Democratic National Committee will be saying it's the beginning of the end for George W. Bush, and if the Republicans win, the Republicans will be saying it foretells a national landslide for Bush," said Larry Sabato, director of the University of Virginia's Center for Politics.

In Kentucky and Mississippi, the GOP looked poised to take control of two states that have long elected Democratic governors. Dual victories by Republicans would show even more erosion of Democratic power in the once "solid South."

Tuesday will also feature legislative races in three states and a host of ballot items ranging from gambling issues to mass transit. In Louisiana, voters go to the polls to select a new governor on Nov. 15 to replace term-limited GOP Gov. Mike Foster.

A Mason-Dixon poll taken in Mississippi late in October showed GOP challenger Haley Barbour would receive 47 percent of the vote while Democratic incumbent Gov. Ronnie Musgrove would get 43 percent.

Barbour, a Mississippi native and former Washington super lobbyist, chaired the Republican National Committee from 1993 to 1997. Musgrove has been attacking Barbour as an out-of-touch Washington insider who has backed trade deals that cost the state blue-collar jobs.

Barbour has accused Musgrove of failing to improve the economy and has argued, with some success in the polls that his powerful connections will help the state grow. The race is the most expensive in Mississippi history.

Voter turnout appeared to be heavy around Mississippi with lines reported after the polls opened.

"In our county it seems like it's wonderful, lines everywhere," said Hinds County Circuit Clerk Barbara Dunn. "I hope beyond all hope that when the day ends, we will have had a turnout like we haven't had in years."

Bush made campaign swings through Mississippi and Kentucky on Saturday. Other GOP leaders, including Vice President Dick Cheney and former New York Mayor Rudolph Giuliani, have also visited Mississippi to campaign for Barbour.

Gubernatorial candidates need to a majority of the popular vote as well as a majority of the state House districts. The Democrats will retain their majority in the 122-member House.

Bluegrass Politics

Bush also put his political capital on the line for the GOP candidate in Kentucky.

"This man has the right values to lead this great state," Bush said of Kentucky Republican Rep. Ernie Fletcher, who is hoping to put the governor's office in the GOP's hands for the first time in three decades.

In Kentucky, term-limited incumbent Democratic Gov. Paul Patton is leaving office in the wake of a sex scandal. Fletcher has been running a "throw-the-bums-out" campaign against Democrats for months.

Although two recent independent polls indicated Fletcher with a nine-point lead among likely voters, Fletcher said Sunday, "We're running like we're 10 points behind."

Democratic Attorney General Ben Chandler has tried to distance himself from the outgoing Patton and has cast the race as a referendum on the quote "Fletcher-Bush economy."

Chandler planned to campaign for more than 24 hours straight before the polls opened.

"It's all voter turnout," Chandler campaign manager Mark Nickolas. "One last swing through the state to remind everybody what sort of governor Kentucky needs."

Mayoral Elections Heat Up

Houston, Philadelphia and San Francisco are holding elections for mayor.

In Philadelphia, Democratic Mayor John Street is fighting for survival after an FBI bug was found in his office as part of a broader probe into alleged city hall corruption.

Republican Sam Katz managed to take a slight lead in the polls recently, but Street has been inching forward by suggesting that the bug was a partisan plant designed to hurt him politically and put a Republican mayor in place to help Bush in 2004.

Katz has dealt with harassment by union activists, an incident in which a person tossed what appeared to be an unlit firebomb into a campaign office and a former employee's claim that the candidate embezzled money from a private business venture.

Katz has campaigned on promises to cut city taxes and end cronyism at City Hall.

Street beat Katz by fewer than 10,000 votes out of more than 430,000 cast in 1999. That fight was resolved on racial lines, when all but a few of the city's black neighborhoods voted for Street. Nearly all its white neighborhoods voted for Katz.

One voter, Catherine Burton, 70, said Tuesday morning that she voted for Street and approved of his record.

"He's helped the neighborhoods," she said. "He's building homes for people who never had them, for the young people who never had homes of their own. That means something, that means everything.

"But another said she jumped party lines to vote for Katz. "I think the city needs a change and don't think Mayor Street has done enough to engage my vote, and I'm a Democrat," said Nina Pritzker-Cohen, 36, an interior designer.

In other campaigns around the country, two millionaire Democrats were the leading candidates to replace term-limited mayors named Brown in Houston and San Francisco's non-partisan elections.

Bill White, a former Clinton administration deputy energy secretary who spent $2.2 million of his own money on his campaign, was leading a field of nine to replace Houston Mayor Lee Brown.

Gavin Newsom, whose proposals to cut cash subsidies to the homeless was a surprise hit in famously liberal San Francisco, was the favorite to replace Mayor Willie Brown.

Both top vote-getters in Houston and San Francisco were all but certain to face the second-placing candidate in runoffs.

Gambling, Transit, Primaries, and More

Voters could break the Republican-Democratic tie in New Jersey's state Senate, and Virginia and Mississippi will also hold legislative elections. Voters will decide on gambling issues in Maine, Indiana and Colorado; mass transit in Houston, Tucson, Ariz., and Kansas City, Mo.; and an anti-stress proposal in Denver.

Two cities were considering changes in the way they pick their mayors.

In New York City, voters were deciding whether to eliminate party primaries for municipal offices and make all city elections non-partisan. Republican Mayor Michael Bloomberg spent at least $2 million of his own money to support the measure.

Democrats feared it would weaken their influence in a city where they outnumber Republicans 5-to-1, but many leading Republicans, as well as most of the city's major newspapers, also opposed the proposition.

In Richmond, Va., former Gov. Doug Wilder was behind a referendum that would have the mayor directly elected rather than appointed by the city council.

San Francisco voters also must decide whether the city sets its own minimum wage. The proposition would impose an $8.50-per-hour minimum wage on all employers. If passed, it would be the third such law in the nation.

Fox News' Carl Cameron and The Associated Press contributed to this report.