(CNN) -- Republicans have won eight of the last 10 presidential elections in Nevada, but the state is increasingly becoming a battleground in presidential politics.
Jobs in the Las Vegas service industry are drawing new residents to Nevada.
Former President Clinton won Nevada in 1992 and 1996, and Sen. John Kerry came close in 2004. President Bush beat Kerry there by two percentage points -- 50 percent to 48 percent.
Much of the political shift is due to the state's population boom. The 1970s and '80s saw an influx of mostly white Reagan Republicans.
But these days, Nevada is one of the fastest-growing and most diverse states, with one in every five people Hispanic and a heavily unionized work force.
"Demographic changes have worked to the advantage of the Democratic Party here, and now we see the Democratic Party opening up a sizable voter registration increase over the Republicans," said David Damore, a political science professor at the University of Nevada, Las Vegas. "That's something they have not had here."
As Rep. Shelley Berkley, a Democrat who represents Las Vegas and southern Nevada, points out, "I've got the fastest-growing congressional district in the United States with 1.9 million people. We have 5,000 new residents a month coming into town."
Young people with families are drawn to Las Vegas by new jobs in the booming service sector, and the city has the fastest-growing Asian and Hispanic populations in the country, according to the U.S. Census Bureau.
"We build a school a month in order to keep up with the growth," Berkley said, noting that her congressional district also has the fastest-growing senior population.
Republicans still do well around Reno, Lake Tahoe and the lightly populated rural counties, but Democrats are gaining ground in Las Vegas and the surrounding areas of Clark County, home to 70 percent of the state's population.
Nevada Democrats and Republicans will hold caucuses Saturday to show support for their choices for president, but most of the attention will be on the Democratic race. The Republican presidential candidates are focusing on the South Carolina primary that's held the same day.
Region by region
Dominated by Reno, Nevada's second-largest city, Washoe County is traditionally a Republican stronghold. Its economy is based on gambling. Lake Tahoe also is in the county, along the state's western border with California.
At the southern point of the state, Clark County has become one of the fastest-growing metro areas in the country -- affluent, unionized and increasingly Democratic. Gambling and the associated hotel, food and entertainment industries dominate the economy, but high-tech firms also are moving to the Las Vegas Valley.
Between Washoe and Clark are rural counties, including uninhabited mountains and desert. The area contains small communities as well as portions of the wealthy Tahoe basin and the state's capital, Carson City. The region tends to vote Republican.
The two major Las Vegas newspapers each endorsed a different candidate in the Democratic contest.
In a Friday editorial, the Las Vegas Sun tapped Sen. Hillary Clinton of New York as "the right choice."
"Clinton has a long and substantial record of leadership fighting on behalf of working Americans and children, and it is this experience and her passion for creating a better country that would serve this nation so well," the newspaper said.
"Our country needs someone who can be president from Day One after taking the oath of office. Her steadiness and resolve certainly would aid us in re-establishing better relations with other nations after [President] Bush's go-it-alone foreign policy, not to mention a thoughtful and responsible policy regarding our combat troops in Iraq."
The Las Vegas Review-Journal, the state's largest newspaper, on Wednesday backed Sen. Barack Obama of Illinois but only half-heartedly.
In its endorsement, the Review-Journal seemed to perceive Obama as the lesser of three evils.
After a lengthy criticism of Clinton and a one-sentence swipe at the "anti-capitalist populism" of former Sen. John Edwards of North Carolina, the editorial asked, "Is Barack Obama, then, the ideal Democratic candidate for president? Hardly."
The editorial then went on to criticize Obama's lack of experience and dismiss his message of change. "His policy recommendations -- when he can be convinced to get any more specific than 'I represent change' -- are the opposite of 'change.' They're old-line, welfare-state solutions that haven't spent enough time in the microwave to appear even superficially appetizing."
Of the four paragraphs that address Obama directly, only one compliments him. "Barack Obama is, at least, likable," adding "he is a good politician, in the non-insulting sense that he knows how to speak to individual Americans and give them the feeling he cares about their concerns."
In the GOP contest, the Review-Journal endorsed former Massachusetts Gov. Mitt Romney.
The Review-Journal editorial praised the candidate's business background, saying, "Mr. Romney has extensive experience in the private sector, which is unusual for far too many politicians."
The Sun didn't endorse anyone in the Republican race. E-mail to a friend
CNN's Alexander Marquardt and Bill Schneider contributed to this report.