In a Minnesota congressional delegation with three first-term members and a newcomer arriving in January, John Kline and Betty McCollum have been moving up the seniority ladder. Kline, a Republican, has represented the Second District since 2003, and McCollum, a Democrat, is completing her fourth term from the Fourth. Both won reelection by strong margins two years ago and now are trying to fend off new opponents. A look at the races in the two districts: THE SECOND: KLINE vs. SARVI Two years ago, facing a challenge from an ex-FBI agent named by Time magazine as its "Person of the Year," Rep. John Kline flooded the households of his district with mailings attacking her -- and triumphed by 16 percentage points.

This year, facing an Iraq war veteran as ramrod-straight as himself, Kline has been more subdued. In their first debate, only once or twice was he drawn into responding to Democrat Steve Sarvi's attacks.

But it won't surprise too many people if the result is much the same. Even in a district trending more Democratic, national campaign-watching services are rating Kline as a decisive favorite.

Sarvi aides say the competition for donors this year has been tough, with a ferocious race going on in the adjacent Third District and an intense contest for U.S. Senate.

Kline did seem to create an opening for a challenger by becoming one of just a dozen members of Congress to turn his back on earmarks, the process by which Congress doles out millions in road and transit dollars to its members, with emphasis on those with heightened seniority who belong to the right committees.

In a district with lots of traffic congestion in the mornings and evenings and a keen desire for roadway improvements, that sent eyebrows rising. Kline this month has acknowledged the issue as a delicate one for him by issuing a television ad attacking earmarking.

He says the process is "corrupt and corrupting," and ends up with more money going to bike paths for an influential figure like Democratic Rep. James Oberstar, who represents northeastern Minnesota, than for roads and bridges in a fast-growing suburban district like his own.

Sarvi has hesitated to really zero in on that issue. As a junior member of Congress, Kline never got all that many earmarks anyway. And voters hear constant attacks on earmarks.

Instead, much like Kline's 2006 opponent, Coleen Rowley, honored by Time for her role as an FBI whistleblower after 9-11, Sarvi has gone after Kline on a seeming strength: his commitment to veterans, in funding for their needs and concern about their condition. Sarvi has pointed, for instance, to a Kline comment during a congressional hearing that he claims pooh-poohed the importance of post-traumatic stress disorder.

In response, Kline aides produced a full transcript that they say proves the comment was taken out of context and doesn't minimize PTSD at all. Kline also notes that he played a key role in bringing Minnesota's widely praised "yellow ribbon" program for returning vets, making a special effort to look after their needs, to other vets around the country.

DAVID PETERSON

Not since 1948 has a Republican represented Minnesota's Fourth Congressional District, centered in St. Paul and currently held by Democrat Betty McCollum. Now, as McCollum, 54, seeks a fifth term, a 35-year-old attorney and certified public accountant has taken on the challenge of running against her.

Republican Ed Matthews is a relative newcomer to politics and a fiscal conservative. He's made controlling government spending and reducing taxes a top priority in his campaign. He opposes congressional earmarking and wants to make permanent the 2001 and 2003 Bush tax cuts. He also favors a flat tax over the current tax code, which he says is too complicated.

McCollum calls herself a "progressive voice." Elected in 2000, the former substitute teacher became only the second Minnesota woman elected to Congress.

Since then, McCollum's profile in the House has been rising. She sits on two influential committees - Appropriations, and Oversight and Government Reform. McCollum ranks among the most loyal Democrats in House votes.

At a time when economic worries dominate voters' concerns, the candidates have contrasting views on how to revive the U.S. economy. Matthews was opposed to the $700 billion bailout legislation that Congress passed and has said making the Bush tax cuts permanent would help get the economy moving again.

"We should not spend $700 billion on a bailout for Wall Street, some of which will go to golden parachutes for executives that were reckless," Matthews said at a recent candidates forum. "The current Congress is responsible for this mess and it's time for change in Washington."

McCollum supported the bailout bill. "I did support the rescue package because people need to know that their retirement savings are protected, their children's college is protected and in that bill there are no golden parachutes," she said. "And in the legislation that I voted for, taxpayers will be repaid in full."

ALLIE SHAH

COMING MONDAY: A look at the congressional races in Minnesota's Seventh and Eighth districts.

THE FOURTH: McCOLLUM vs. MATTHEWS