The state's population is largely urban with more than half of Coloradoans living in the metropolis of Denver, and four-fifths occupying a highly developed strip that parallels its Front Range -- where the Rocky Mountains jut out from Colorado's plateau.

The pattern of economic boom and bust and population changes date back to the 1850s when a gold mining boom attracted the first settlers. As gold mining died down, the state hit an economic slump that was eventually overcome by a silver boom. The state's economy cycled downward again in the 1930s with the Great Depression but was revitalized after World War II when its great outdoors attracted skiers and tourists.

As the postwar tourism boom continued, Denver grew into a meatpacking, banking and manufacturing center. In the 1970s, Denver became a regional center for the federal government and new businesses continued to build up the city. Ski resorts, year-round mountain condominiums and new buildings shot up around Denver as the region continued to grow.

In the 1990s Colorado began its latest boom -- a technology and telecommunications burst that has built up its largely Republican suburbs. Good jobs and outdoor attractions have brought highly skilled workers to Colorado. For this reason, the state's 4.5 million population continues to grow, as do the number of entrepreneurs and tech-savvy workers.

The state ranks seventh in per capita income and second in the nation for college graduates. Its economy grew by more than 6 percent annually throughout much of the 1990s and by 8.8 percent between 1999 and 2000.

Many families come from California and Texas to take advantage of the high tech growth. Primarily white and affluent, they tend to move to the suburbs and keep Colorado's conservative base growing.

"Colorado is a conservative state and is becoming more conservative," University of Colorado at Denver Professor Tony Robinson said. "For everyone who moves into the state and registers to vote, two of them register Republican."

Currently, Republicans outnumber Democrats by roughly 188,000 voters.

But Colorado, especially Denver, also has attracted a lot of Latinos -- a population that tends to lean Democratic.

The Latino influence may be muted, however, by the fact that less than half of the eligible Colorado Latinos voted in 2000's presidential election.

Its major cities and their suburbs, then, remain politically separated. Boulder, Denver and Pueblo, cities located in the central and north central areas of the state, are heavily Democratic. The environmentally friendly, slow-growth Democrats from the 1970s, who built the outdoor sports shops, vegetarian restaurants and pedestrian malls of this region, remain there today.

But the newcomers to the state tend to migrate to Colorado Springs, a south central suburb that is a highly conservative Republican region. Colorado's eastern plain, a farming community, also remains heavily conservative.

The western mountainous side of the state replicates its eastern counterpart as heavily Republican -- except for the San Luis Valley, which is rural, Latino and low income. This region, a neighbor of the more liberal New Mexico, remains a Democratic stronghold.

Historically, the state has voted Republican, with a few notable exceptions. Colorado's primarily conservative voters tend to focus on tax rates, suburban quality of life, urban sprawl, pollution and traffic as key issues, Robinson said.

But in the 1970s, during the energy price boom, a steady stream of Democrats gained local and national office by promoting slow-growth. Democratic Gov. Dick Lamm, Sen. Gary Hart, Rep. Patricia Schroeder and Rep. Tim Wirth were all part of this movement.

Democrats controlled the governor's office from 1974 to 1998. Despite the Democratic stronghold on the governorship, however, Republicans ruled the legislature, making Democratic legislation difficult to pass.

A changing national economic and political atmosphere combined with population surges has tipped the state more conservative -- especially in the religious, family-oriented Colorado Springs. Since the 1990s voting trends have remained conservative, only wavering under economic or population-change pressure.

Conservatives passed two key referenda in the early 1990s. In 1990, Colorado set term limits, becoming the first state to pass such legislation. Then, in 1992, Colorado passed a law requiring a popular vote to raise taxes.

Still, Democrats have held on to some offices. Coloradoans elected Rep. Ben Nighthorse Campbell to the U.S. Senate and former President Clinton carried the state in 1992.

But a new GOP wave soon swept the state. Campbell switched parties in 1995, marking the first time in over 20 years that Republicans controlled Colorado's two U.S. Senate seats. In 1996, Colorado was one of only three states to switch its vote from Bill Clinton to Bob Dole in the presidential election. The state also elected Republican Wayne Allard to the Senate that year. In 1998, Republicans took the governor seat, electing Bill Owens as its first GOP governor since 1970. Republicans also maintained their dominance in the state House.

In 2000, President Bush easily carried the state. In 2002 the Republicans gained even more ground in Colorado as Owens and Allard were reelected, Republicans kept their hold on the state House, regained a majority in the state Senate and nabbed Colorado's new 7th Congressional District.

Republicans did lose a referendum that would have limited Spanish-language bilingual education to one year, but this was one of their only losses to Democrats in 2002.

In spite of recent GOP dominance, 2004 seems to be up for grabs. With a U.S. Senate race in the works that pits a big-time Republican business executive versus a Democratic two-time statewide office holder, the race is looking tight.

And the stakes are high. The Senate race, according to many pundits, could determine who takes the state in the presidential election.

Based on Colorado's volatile voting history despite its grounded conservative roots, the state could be looking at another changing political scene.