Obama to mark first 100 days with stop today in Arnold, Mo.

ST. LOUIS -- President Obama will continue a political tradition when he uses Jefferson County -- a bellwether county in a swing state -- as a venue for national business this week.

Obama will mark his first 100 days in office today with a town hall meeting at Fox Senior High School in Arnold, a growing suburb south of St. Louis.

While Missouri officially lost its status as a presidential bellwether state in November when it voted for Republican John McCain, Jefferson County voted for Obama.

"We're the heartland, a microcosm of the country," Jefferson County Executive Chuck Banks said. "And we typically vote the way the country votes."

Some other politicians have visited the same school. Obama's running mate, Joe Biden, pledged to help the middle class during a campaign stop at the high school in the lead-up to the November election. Bill Clinton and Al Gore held a flood summit in the school cafeteria during the Great Flood of 1993. And vice presidential candidate Dan Quayle came to the school two weeks before the 1988 election.

Fox High School principal Kevin Rossiter said the county is popular with politicians who want to use a slice of middle America as a backdrop for their message.

"Apparently we're getting pretty good at it," he said, "because they keep asking us."

The White House said Obama chose to come to Missouri because its "families and workers have felt the impact of the economic crisis as much as anyone."

Jefferson County has rural and suburban elements and is the home of Gov. Jay Nixon and former New Jersey senator Bill Bradley.

The county has a largely blue-collar work force that is heavily unionized, Banks said. The No. 1 industry is home building, which has taken a hit in the recession. Banks said more than half of county residents identify themselves as Democrats to pollsters, but voters there usually pick the winner in presidential elections.

Other industries include lead smelting and cement production, bottling and health care. Sixty percent of residents drive out of the county to work.

"It's the heart of the country in terms of population," said Terry Jones, professor of political science at the University of Missouri-St. Louis, adding that Arnold is in the middle of fast-growing suburbs, "where the balance of electoral power is."

It also helps that Jefferson County is near the state's largest media market.

Ken Warren, St. Louis University professor, pollster and author, said Obama's visit to Missouri on his 100th day in office is strategic, not only because the state will be in play for the 2012 election, but to aid Secretary of State Robin Carnahan, a Democrat, in her bid for the Senate seat being vacated by longtime Sen. Kit Bond, a Republican.

Carnahan's office confirmed she will be with the president today.

"Politics never goes away," Warren said. "He's doing the intelligent political thing of killing two or three birds with one stone. He's looking at 2012 for himself in a clear battleground state and at 2010 for fellow Democrats."

He recalled that in 2002, President George W. Bush made repeated visits to Missouri and helped Jim Talent beat Jean Carnahan for her Senate seat.

Warren said that from Franklin Delano Roosevelt to John Kennedy, Dick Cheney and Bill Clinton, politicians always have come to Missouri.

"It's a good place to go," he said. "It's in the heartland."