The GOP race for delegates means the approach to winning the nomination is different than it's been in decades. One sign of that -- the personal attention from the candidates. Ted Cruz will be addressing the Colorado State GOP Convention Saturday, as well as the Republican Jewish Coalition. John Kasich is sending John Sununu, a former U.S. senator, as a surrogate; and Donald Trump had also scheduled an appearance this week but changed course when it was clear his campaign would not win many delegates, having been largely outmaneuvered by Cruz.

The Texas senator has built a strong organization in the state, based on a volunteer network. His team has been campaigning aggressively in the rolling caucuses in its seven congressional districts.

Trump has just a few people on the ground in Colorado who will go through the process, reports CBS News chief White House correspondent Major Garrett. The delegate selection game started months before Trump was a candidate and the Trump ground forces are not well-organized as a result. "We are a day late and a dollar short," said Barry Bennett, a Trump adviser. "We don't have high expectations in Colorado."

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Trump isn't expected to rack up many delegates in Colorado, according to Becky Mizel, who's running to be a Trump delegate. She told CBS News many of the people who participated Friday were Cruz supporters.

"For us, a lot of the people here today are Cruz people, there's no doubt about it. There are a lot of Trump people here, and they're very glad we have some sort of showing for Mr. Trump here. He didn't have to do anything but he wanted the Trump people to have some kind of support today and tomorrow," Mizel said. "To be honest, I'm not even sure we'll take any delegates, we're kind of expecting not to really get delegates here."

Colorado's slate of Republican delegates are expected to be finalized Saturday at the state party's convention in Colorado Springs.

The state will send a total of 37 delegates to the Republican National Convention this July and unlike most states, their selection is not the result of a regular primary or caucuses.

Colorado opted not to hold caucuses, and as a result, the delegates will have been selected through a series of county elections that that the state has held over the course of the last week.

Congressional districts elect 21 delegates as well as alternates and the state convention selects 13 delegates as well as alternates. The remaining three unpledged delegates are the national commiteeman, national committeewoman and the state party chairman.

This slate could be key if Republicans face a contested convention in Cleveland. Delegates could either run by pledging supporting for a particular candidate or they could run unpledged. For those who have pledged support, they are only bound to vote for that contender on the first ballot. After that, they could vote for whomever they want.

At the state convention on Saturday, 600 people will compete for the 13 open slots. According to The Denver Post, Cruz has picked up nine delegates who have either formally pledged to support him or have suggested they would. A candidate will have to win 19 delegates in order to claim victory in Colorado, the report said.

CBS News' latest delegate count has Trump with 743 delegates, Cruz has 506 and Kasich has 143.

CBS News' Alan He contributed to this report.