This year's mid-term elections give voters a choice that's dramatically different from recent contests. For much of the last decade, values and national security have played central roles in the two parties' struggle for power.

In 2010, the election focuses squarely and unequivocally on the economy—who has a job and who doesn't, whose taxes will go up and whose won't, whether the government has taken the right steps to turn around the economy and what do in 2011 to increase growth and reduce deficits.

The choice in unusually clear because a single party—Democratic—has controlled both the White House and Congress for the last two years. And that governing party has managed to push through a broad and costly agenda reaching into every significant corner of American life and business.

Democrats argue they've turned around a plummeting economy and laid the foundation for future growth; minority Republicans insist that agenda has pushed America dangerously deeper in debt without results, as evidenced by the 9.5% unemployment rate.

CNBC will track several key mid-term election contests that, in different ways, distill the dollars-and-cents dilemmas facing Americans as they choose new representatives, senators and governors this fall. Click ahead to see who is on the line and what is at stake.

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John McCain (R), pictured left, won against former congressman J.D. Hayworth (R), pictured right, in a close Republican primary August 24. Hayworth had positioned himself as a more conservative candidate. Now McCain faces Tuscon Vice-Mayor Rodney Glassman (D) in the general election.

This race pits three-term Democratic incumbent Barbara Boxer (left), who worked her way up from local government, and political newcomer and former Hewlett-Packard CEO Carly Fiorina (R), who cut her political teeth as fundraiser and economic advisor for Sen. John McCain in the 2008 presidential race.

The former eBay CEO Meg Whitman (R) (pictured right) is running against Democratic nominee and Attorney General Jerry Brown (pictured left) in a state facing deep budget problems. Brown served as governor 1975-1983.

Tea party favorite and current District Attorney Ken Buck (R) (photographed at left) is facing incumbent Michael Bennet (D) (pictured right) for the seat.

In Connecticut, Republican Linda McMahon (pictured left), co-founder and former CEO of World Wrestling Entertainment, defeated Rep. Rob Simmons, a former congressman who suspended his campaign in May only to jump back into the race a month later. McMahon faces Democrat Richard Blumenthal (right), the state's attorney general, who stepped into the race when long-time incumbent Chris Dodd decided to retire. 

CNBC's John Harwood interviews: Blumenthal  McMahon

Conservative Christine O'Donnell (left) pulled off a stunning upset over nine-term Rep. Mike Castle in the Republican Senate primary in Delaware, propelled by tea party activists into a November showdown with Democrat Chris Coons (pictured right.)

Instead of seeking re-election, current Florida Governor Charlie Crist (far left) is seeking to fill the Senate seat of George LeMieux, the temporary replacement for Mel Martinez, who resigned in September.

Crist switched parties in the process and is now an Independent. He faces Republican Marco Rubio (center), former speaker of the Florida House, as well as Representative Kendrick Meek (D).

Republican Party nominee Rand Paul (R), pictured at left, is a Tea Party favorite, and son of long-time U.S. Congressman Ron Paul of Texas. Kentucky Attorney General Jack Conway (D), pictured at right, is the other candidate for the seat of former baseball star Jim Bunning, who is retiring after two terms.

Incumbent Democrat Martin O'Malley (right) and his predecessor, Robert Ehrlich (R), are in a tight race with polls showing either candidates could win the election. Though the race is seen as something of a national proxy, the state's jobles rate is well below the national average. Maryland, however, faces $2-billion budget shortfalls for fiscal years 2010 and 2011.

John Hardwood on the race.

Senate majority leader and incumbent Harry Reid (D) is facing tough competition from former State Assemblywoman, and Tea Party favorite, Sharron Angle (R). Reid is seeking a fifth term.

Democrat Carolyn Maloney (left) and chair of the Joint Economic Committee easily beat hedge fund lawyer and ex-Clinton aide Reshma Saujani (D), winning over 80 percent of the vote during a Sept. 14 primary. Saujani—who ran as an ally of the financial industry and accused the liberal Maloney of going too far in criticizing her hometown industry.

Maloney, who has held her seat since 1993, now faces David R. Brumberg (R) in the general election.

John Harwood interviews Saujani.

Mary Jo Kilroy (D) and Steve Stivers (R) square off in the general election, as she defends her votes for health care and financial regulation bills by attacking Republican opponent Steve Stivers as tainted by his background as a bank lobbyists.

Capital Markets Subcommittee chair Paul Kanjorski (D), pictured at right, will face current Hazleton, Penn. mayor Lou Barletta (R) in an effort to keep the seat he’s had since 1985. Kanjorski raised his profile considerably in the current Congress by helping to craft a package of financial reforms but unemployment in his state is high.

Congressman Joe Sestak (D) beat Republican-turned Democrat incumbent Arlen Specter—who has held the seat for five terms—in the May Democratic primary. Sestak (pictured far left) is now in a close race with Republican Pat Toomey (pictured right), a former Congressman who lost to Specter six years ago, and current Club for Growth president.

John Harwood on the race.

Interview with Toomey.

Democrat John Spratt (right), budget committee chairman, is trying to hold on to his seat as Republican nominee Mick Mulvaney (R) gains more support and funding.

In rural Virginia, Democratic incumbent Tom Perriello (left) makes a case for continuing the Obama agenda and tries to cast Republican opponent Robert Hurt as a tool of Wall Street and utilities interests.

John Harwood on the race.