While discontent with the status quo has shifted support toward Republicans running for the U.S. Senate, local issues have endangered governors from both parties. A look at 12 races people will be talking about:
Alaska: Walker vs. Parnell
Republican Gov. Sean Parnell is in trouble after the Democrat and independent candidates teamed up on a unity ticket headed by independent Bill Walker, a onetime Republican.
Polling in Alaska is notoriously difficult, but the race is certaintly a close one.
Fallout from two local issues have made Parnell vulnerable: His handling of a sexual-assault scandal inside the Alaska National Guard and an oil and gas tax measure passed in 2013. The unpopular law was challenged in an August referendum and narrowly survived repeal.
The incumbent believes Walker ultimately will be hurt by his association with Democrat Byron Mallott, who is now running for lieutenant governor. The Democratic brand is still unpopular in Alaska.
Walker has the support of the state's Democrats and could benefit from the strong organizational effort by Democratic Sen. Mark Begich, who seems to be pulling away from his opponent in his bid for a second term.
Why it matters
If it's successful, the highly unusual maneuvering that resulted in the Walker/Mallott unity ticket could set the stage for similar deals in local and statewide elections elsewhere.
Arizona: DuVal vs. Ducey
Despite its conservative voters, Arizona often elects Democratic governors. This year, though, Republican state Treasurer Doug Ducey leads in most polls over Democratic businessman Fred DuVal, in the race to succeed retiring Gov. Jan Brewer, a Republican.
A bruising six-candidate Republican primary left Ducey struggling, but he has rebounded with an aggressive campaign focused on the economy.
DuVal portrays himself as a bipartisan outsider and has promised to focus on ethics and changes to lobbying rules if he's elected.
A hot topic in the race is state legislation that would have offered a legal defense for people and companies facing discrimination lawsuits if they could prove they acted on a "sincerely held religious belief." Brewer vetoed the bill.
DuVal demanded a veto a day after the measure passed. Ducey said quickly that he would have vetoed it, but suggested trying to forge consensus on language "protecting religious liberty."
Why it matters
Republicans hope efforts to turn out the vote in the governor's race will help the GOP pick up a pair of House seats held by Democrats. But DuVal is a Tucson native, which could help vulnerable Rep. Ron Barber in the Second District.
Colorado: Hickenlooper vs. Beauprez
Democratic Gov. John Hickenlooper faces a tough challenge from former Republican U.S. Rep. Bob Beauprez.
Hickenlooper opposed the vote to legalize recreational use of marijuana, but has had to manage the law's implementation. Republicans and social moderates who oppose legal pot use suggest he has steered the swing state too far to the left.
He has attempted to distance himself from the law, but backlash threatens his chances against Beauprez.
Ads attacking Hickenlooper's record and leadership are helping to boost the challenger.
Hickenlooper announced early in the campaign that he would not turn to negative ads, a decision that might be hurting him.
The state's unemployment rate has fallen from about 9 percent when the governor took office to 5.1 percent, but Republicans say Colorado's growth is anemic compared with its neighbors.
Why it matters
A Hickenlooper loss would raise doubts about the durability of recent Democratic gains in a state that legalized marijuana and passed tough new gun laws, but recoiled at raising taxes to fund schools. Other states considering looser pot laws will be watching, too.
Connecticut: Malloy vs. Foley
Democratic Gov. Dannel Malloy is trying to fend off Republican Tom Foley, a former ambassador to Ireland. The race in this traditionally liberal state has tightened. It's a rematch of the 2010 election, which Malloy won by fewer than 6,500 votes.
The latest polls show the race is tied, suggesting that Malloy's attacks on his Republican challenger, who had been up 6 points, have been effective.
Malloy and outside groups that support him have aired negative TV ads depicting Foley as a cold-hearted businessman who can't connect with middle-class citizens.
Foley has tried to fight back with ads featuring his wife and young twins, but he also has blasted Malloy's economic policies. In one, Foley's campaign says Malloy would increase taxes if he is re-elected. Malloy has promised not to do so, but he has alienated labor with tax hikes and cuts in union benefits.
Large political action groups have spent almost $8 million on the race.
Why it matters
A Malloy loss in this very blue state could be an indicator of a good night for other Republican candidates across the state — and perhaps even across the country.
Florida: Scott vs. Crist
In one of the nation's closest, costliest and most-watched governor's races, Republican Gov. Rick Scott narrowly trails Charlie Crist, a former Republican governor who switched parties and is running as a Democrat.
A third candidate, Libertarian Adrian Wylie, seems likely to siphon votes away from both candidates.
The key question in this campaign could decide the fate of other GOP candidates: Who gets credit for an economy that is stronger than when the incumbent took office?
Scott is promoting Florida's revitalized economy and his drive for $1 billion in tax cuts, along with more funds for schools.
Crist pledges an increase in the minimum wage, lower insurance rates and a fight for women's and gay rights.
Scott is expected to spend at least $100 million in the race, much of it to fund the negative advertisements that have characterized both campaigns. Crist doesn't have as much cash.
Why it matters
More than most gubernatorial races, this one has broad 2016 implications: Who will control the levers of government in the nation's fourth most populous state — one that has been memorably decisive in presidential elections?
Illinois: Rauner vs. Quinn
Democratic Gov. Pat Quinn and his Republican opponent, venture capitalist Bruce Rauner, are engaged in a personal brawl.
Neither candidate has satisfied voters with a plan to deal with the state's fiscal woes: its crushing pension debt, the lowest credit rating in the U.S. and a budget that will dry up next year if elevated income-tax rates expire as scheduled, cutting annual revenue by about 14 percent. Chicago, meanwhile, has $4.6 billion in unpaid bills and $100 billion in unfunded pension liabilities.
Quinn paints Rauner as a man out of touch with average wage earners, citing his $53 million in income in 2012 and his $140,000 wine-club membership.
Rauner links Quinn to imprisoned former Gov. Rod Blagojevich, whom Quinn succeeded after serving as lieutenant governor. The challenger also points out that a federal investigation is focused on a 2010 anti-violence program that Quinn started.
Rauner, who says he can duplicate his business successes in office, has donated about $13 million to his own campaign.
Why it matters
Quinn's unpopularity is a drag on other Democrats and is motivating GOP voters. A Quinn loss could shake up the state's entire power structure.
Michigan: Snyder vs. Schauer
Republican Gov. Rick Snyder, the former CEO of Gateway computers, is being challenged by a Democrat with an unusual strategy at a time when career politicians are being viewed with skepticism: Mark Schauer is emphasizing his experience in the U.S. House and the state Senate.
Most polls show Snyder, a possible 2016 presidential candidate, with a slim lead in an unexpectedly tight race.
The incumbent, whose brand is built around his sunny outlook, had been reluctant to attack his opponent. But in an Oct. 12 debate, he defended his record and ripped his opponent, noting that Schauer was Democratic leader in the Michigan House during a state government shutdown and linking him to Washington-style politics.
Schauer has attacked Snyder for cutting $1 billion from public schools, raising taxes on pensioners and giving senior aides huge pay increases.
Another hot issue is Detroit's municipal bankruptcy. Snyder says he appointed an emergency manager after exhausting all other options, while Schauer said it usurped democracy.
Why it matters
Anything less than a convincing win would put a dent in Snyder's national political ambitions.
Wisconsin: Walker vs. Burke
Incumbent Republican Gov. Scott Walker, who overcame a 2012 recall effort to oust him, faces a strong challenge from Democratic business executive Mary Burke.
The recall effort came after Walker rescinded some of the bargaining rights of public employee unions. His survival — he was the first governor in U.S. history to withstand a recall election — is testament to his political skills and his state's current appetite for fiscally conservative policies.
On the other hand, polls show that Walker has alienated plenty of centrist voters and moderate Republicans. Burke hasn't been able to capitalize on his weaknesses and has been criticized for being bland and inexperienced.
In the campaign's final weeks, taxes have become a contentious topic. Burke rejected Walker's plan to replace the gas tax with a sales tax and said she's open to boosting the gas tax, increasing fees and other ways to hike transportation funding.
Why it matters
Walker's 2016 presidential ambitions would evaporate if he loses his re-election bid. If he wins, he'll have a launching pad for higher office and the swing state will pivot into comfortable territory for the GOP presidential nominee.
