BOISE, Idaho (AP) — Former Vice President Joe Biden won Idaho's Democratic presidential primary Tuesday, defeating Vermont Sen. Bernie Sanders.

Biden and Sanders were vying for the state's 20 delegates to the party's national convention in Milwaukee, Wisconsin, this summer.

Idaho was among the smaller prizes on Tuesday with Biden already having won Michigan, Missouri and Mississippi. Washington and North Dakota were also holding primaries.

It was the first time Idaho Democrats used a primary. In 2016 they used a caucus to select Sen. Bernie Sanders over Hillary Clinton. President Barack Obama handily won the Democratic contest in Idaho over Clinton in 2008.

Sanders didn’t make a stop in Idaho during the 2020 campaign, though he spoke at a few Idaho rallies in 2016. Biden held an Idaho event in August, drawing more than 100 donors.

Brea Barnett, 29, of Boise said she voted for Sanders as the candidate she saw as the best to promote health care, the environment and fair wages.

“He stands for the people,” she said.

Sarah Collins, 32, voted in the Democratic primary but declined to name her candidate.

“I believe in human rights and everybody being treated equally,” she said, noting key issues for were were abortion rights and transgender rights.

Officials predicted the switch to a Democratic primary this year from a caucus could significantly increase the number of participants, and play a role in the outcome.

Biden built a small lead early that fluctuated in the hours after polls closed but never trailed. In highly populated Ada County, Biden had nearly 48% of the vote to Sanders' 45%.

Sanders won handily in Latah County, which includes Moscow and the University of Idaho. But Biden dominated much of the rest of the state and trailed narrowly in only a few other counties.

President Donald Trump had little difficulty winning the Republican primary, and is expected to do the same in the heavily Republican state in the November general election. He got Ruth Kyle's vote on Tuesday.

“I think he's doing a great job,” she said. “He's just got the economy going full blast."

Idaho last year was the nation's fastest-growing state, with close to 37,000 new residents boosting its population to nearly 1.8 million. That's a 2.1% population increase.

In the past decade, according to the U.S. Census Bureau, the deeply conservative state has seen a population jump of more than 200,000. Studies indicate many have come from liberal-leaning California, Oregon and Washington.

But it's not clear if those new residents are bringing blue-state politics or are Republicans fleeing the coast for conservative Idaho.

Jaclyn Kettler, a Boise State University political scientist, said it appears Democrats, in general, are moving to urban areas and Republicans to more rural areas, continuing the urban-rural divide between Democrats and Republicans prevalent in states in the U.S. West.

The House went from 11 to 14 Democrats in the 2018 election. Democrats flipped four urban district seats, but lost an urban district in northern Idaho after the incumbent Democrat ran for governor.