South Dakota is a state in transition. Originally a farm and ranch state, the latest census data indicated that the metro areas of the state, in particular Sioux Falls, exploded while the farmland that once was the heart of the region continued to empty during the 1990s.

Republican leaders of the state adopted an aggressive program of attracting new businesses to South Dakota -- a state with no corporate or personal income tax and a large, low-wage workforce.

Drawn by a burgeoning financial services industry and other new firms, like Gateway Computers and NordicTrak, the population of Sioux Falls grew by 24 percent in a state where the total number of people grew by .2 percent.

The winds were shifting in the state's employment picture as well. By 2001, financial management powerhouse Citigroup had become the state's largest employer, edging out the meatpacking firm of John Morrell, which had held the spot for decades.

Founded among the Black Hills and rolling plains, South Dakota was originally controlled by the Sioux Indians, who lived off the buffalo that once roamed the prairie by the thousands. Ranchers, recognizing the sweeping hills and fields would also support massive cattle operations, slaughtered the buffalo and established massive farms.

As whites first moved into the state in the late 19th century, farmers established themselves in the southeast corner, east of the Missouri River. As settlements fanned out further west and north, cattle ranchers took over as farms receded.

It was that division -- the farmers versus the ranchers -- that would underscore politics in South Dakota for generations to come. Even in the 1996 Senate race between Rep. Tim Johnson and Sen. Larry Pressler, the 100th meridian that bisects the state, largely marked the division between those counties west of the line that voted for the Republican Pressler and those east of the line that backed Johnson.

Six years later, when Johnson faced U.S. Rep. John Thune, that division remained the bright line between Democrat and Republican. The closely fought campaign re-elected Johnson by only a few thousand votes.

The pioneers who founded the state brought with them fiercely independent, conservative political values. Since South Dakota joined the Union, it has voted for a Democrat for president only four times -- 1896, 1932, 1936 and 1964. The state voted for President Richard M. Nixon in 1972 even though a South Dakotan, Sen. George McGovern, was running against him.

Within the state, politics have been a bit more diverse. Democrats like Johnson and Sen. Tom Daschle have capitalized on populist and agricultural issues. But as the population of "The Mount Rushmore State" edged further from the farm and more towards the suburbs, the Democrats have seen their base dwindle.

"[T]he Democrats' hold may be weakened in the long run, because the farm issues which used to be their chief political asset seem less and less important," Michael Barone wrote in the 2002 Almanac of American Politics. "Population patterns... now look much like those in the Rockies, with most people concentrated around a few cities and towns, while vast acreage remains vacant, punctuated with infrequent ranches and resort areas... South Dakota is not a farm state any more."

This shift has spelled disaster for every Democratic presidential candidate since Lyndon Johnson and may threaten the senate's top Democrat this year.

Despite these demographic challenges, Democrats have countered with a series of closely fought victories for federal office.

The same year Johnson narrowly won re-election, a 31-year-old attorney narrowly lost her first run for Congress. The campaign of Stephanie Herseth shocked many as she mounted a competitive race against political icon and former governor Bill Janklow.

But a tragic car accident re-opened the door for Herseth. Following a deadly car wreck that killed a Minnesota man, U.S. Rep. Janklow was convicted of manslaughter and forced to quit the House. In the special election that followed, Herseth steamed to a narrow victory over state Senator Larry Dietrick.

Now both Herseth and Daschle must fight strong Republican challengers as they hope to continue representing one of the most conservative states in the nation.

-- By Lee Banville, Online NewsHour