Despite a lower jobless rate and a recent uptick in President Obama's approval ratings, Democrats are poised in November to lose their Senate majority and hand over control of Congress entirely to the Republican Party.

With 22 Senate seats up for grabs this fall, Democrats are fighting to hold on to their 53-47 seat majority. They must defend at least seven seats considered "tossups" and are watching three others that could become competitive.

Republicans, who already have a 24-seat majority in the House, need to win just four more Senate seats to achieve a 51-seat majority in that chamber. Republicans already have a head start in Nebraska, where they are favored to snatch away the Senate seat being vacated by Democrat Ben Nelson.

"Even if the economy continues to do better and even if Obama is re-elected, assuming it's not landslide proportions, I would still bet that Republicans will hold the House and pick up the Senate," pollster Ron Faucheux, president of the Clarus Research Group, told The Washington Examiner.

One of the most vulnerable Democratic seats is in Virginia, where Sen. Jim Webb is retiring. But both parties are also expecting heated contests in Hawaii, Montana, Missouri, New Mexico, North Dakota and Wisconsin.

But Faucheux cautioned that Republican victories in any of those states won't come easy.

"The numbers are close enough race by race where it is not a slam-dunk in the Senate and they have to earn it," he said.

Republicans are defending at least two seats of their own, in Massachusetts and Nevada. Losses in either of those states would only extend the odds against a Republican majority.

"I think Republicans need to win just one those two states, either Nevada or Massachusetts," Jennifer Duffy, senior editor at the Cook Political Report. "Then they need to pick up five seats. It's not going to be easy, but it's still doable."

Still, Duffy set the odds of a GOP takeover at "better than 50 percent."

Republicans appear to have a slight edge in both Massachusetts and Nevada, according to polls and political analysts, though both seats are considered tossups.

In Massachusetts, where Republican Sen. Scott Brown is leading Democratic challenger Elizabeth Warren even though Democrats in that state outnumber Republicans 3-to-1. A new Suffolk University poll shows Brown with a 9 percentage point lead, in large part because of his popularity among independents, who make up half of the Bay State's voters.

"You have 60 percent of voters saying that they see a benefit to having a Democratic and a Republican U.S. senator representing Massachusetts in Washington," poll director David Paleologos told The Examiner.

In Nevada, recently appointed incumbent Sen. Dean Heller, a Republican, is expected to sweep the northern, rural part of the state, which he represented in the House. That means his Democratic opponent, Rep. Shelley Berkley, who represents the Las Vegas area, will have to win at least 55 percent of the vote in Clark County, which encompasses the Vegas area.

"That's a large margin of victory in Clark County," Nevada political analyst Jon Ralston said. "The difficult path for Shelley Berkley is to get herself known and liked outside her base in Clark County."