RICHMOND, Va. (AP) — Donald Trump dominated Virginia's coal country in the March GOP primary, but Texas Sen. Ted Cruz's strength with party insiders may win him the support of the area's delegates to the Republican National Convention.

Trump's campaign is set to face a crucial first test of its organizational strength in Virginia when state Republicans begin electing delegates Saturday. Those delegates could ultimately help decide who becomes the Republican presidential nominee at a contested national convention.

A few hundred Republicans are set to gather in Wytheville, a town of 8,000 in the state's southwest corner, to elect three delegates to the Republican National Convention. They will be the first delegates elected in Virginia, with the other 46 delegates being decided later this month and in May at other congressional district conventions and a state convention.

At first glance, the 9th Congressional District's local convention appears to be fertile ground for Trump, whose large margins of victory in the district helped him win Virginia as a whole in the March 1 primary. The district is home to the state's struggling coal country and populated by blue-collar, less-educated and rural voters who have gravitated strongly toward Trump. The billionaire businessman won every single county in the district, with majorities in some counties as high as 60 to 70 percent.

But the Cruz campaign is counting on a superior advantage with party insiders, both in Virginia and around the country, to get its preferred delegates elected.

With a recent loss in Wisconsin, Trump's chances of locking up a majority of delegates before the convention appear to be fading, making the delegate selection process all the more important. Virginia delegates will be bound by the results of the March 1 primary on the first vote, but will be free to vote for whomever they choose if there are subsequent rounds of votes.

To be able to vote in Saturday's event, Republicans had to first get elected at county-level GOP meetings. And some participants Saturday will have to drive more than two hours in the spread-out, mountainous district. Political watchers say these types of party insiders who take the time to register for and attend regional party meetings are more likely to back Cruz.

"The issue is who is going to these conventions," said Terry Kilgore, a Republican state House delegate whose son backs Cruz and is running to be a national convention delegate. "The Cruz people understand the game a little bit better."

Jack Morgan, a Trump supporter and former chairman of the 9th Congressional District Republican Committee, said many Trump supporters are first-time voters who are not familiar with what's involved in running or voting for delegates.

"A lot of Trump supporters are new to the cause," Morgan. "There's an obvious divide between the voters and the party insiders."

Bill Stanley, a state senator and chairman of the Cruz campaign in Virginia, said Cruz deliberately kept enthusiasm up among his grassroots supporters and for finding would-be delegates following the March primary.

"Trump's not been so organized in terms of having contact with people and getting them to run," Stanley said.

But Corey Stewart, a Prince William County official and Trump campaign chairman in Virginia, said the campaign is well-prepared for Saturday's convention. Stewart said the outcome of Saturday's convention should reflect how the district voted in March.

"If the Cruz people try and hijack the convention, that's clearly thwarting the will of the electorate," Stewart said.

Republicans in Northern Virginia's 10th Congressional District will be second to vote for their delegates on April 16.