The Iowa caucuses that we know today can be traced back to the late 1960s and early 1970s.

Current GOP presidential candidates have spent a lot of time and money touring various cities in Iowa beginning in 2023 and continuing this year, specifically ahead of caucus night, in an old-fashioned effort to campaign.

Iowa is typically the battleground state both Democrats and Republicans campaign in. However, Democrats have opted out of the first nominating contest in Iowa. This year, South Carolina will be the location for the Democrat's primary contest as more support for President Biden is expected in the Palmetto State.

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Through a communal decision process, Iowans will get together on Monday and select the candidate they want to represent their party on the general election ballot. The winning candidate is then named, shining a light on where voters stand thus far in the race. 

However, the championed candidate does not immediately earn the GOP nominee for the 2024 presidential election, but rather rustles up bragging rights and a better chance at furthering their campaign trail.

Here are some of the upsets and most notable caucuses over the last five decades.

Iowa caucus 1972: After a push to change the traditional ways of the caucus system from Democrats who believed it was more controlled by "party bosses" as opposed to "responding to grassroots voices and desire," according to the Des Moines Register, Iowa became first in kicking off the election process during the election season. Then-Sen. George McGovern, a Democrat, came in third place with 23% votes, but he gained media attention which helped him in the New Hampshire primary.

Iowa caucus 1976: Jimmy Carter also made it in the news and spent a lot of time in Iowa, which boosted his performance. He ended up gaining 28% of the votes and went on to eventually become president.

Iowa caucus 1988: Then-Sen. Bob Dole won 37% of the votes, calling it "a rather clear-cut victory," as reported by the Los Angeles Times. Televangelist Pat Robertson came in second place with 25%, and then-Vice President George H.W. Bush came in third place with 19%. However, Bush eventually ended up becoming the nominee, winning the presidency.

Iowa caucus 2008: Then-Sen. Barack Obama, who eventually became the president, was up against then-Sen. Hillary Clinton. On the Republican side, former Arkansas governor and Baptist minister Mike Huckabee was up against former Massachusetts Gov. Mitt Romney and the late Sen. John McCain. Obama won 37.6% of the votes, and Clinton came in third place, winning 29.5%. Huckabee won 34.4% of votes from delegates, Romney came in second with 25.4% and McCain in last place with 13.2%.

Iowa caucus 2012: Romney was named as winner of the caucus, beating former Senator Rick Santorum by eight votes. Everything seemed to be smooth sailing after Romney won the New Hampshire primary, and he would have been the first Republican to win both Iowa and New Hampshire in the nominating race. However, just eight days after the primary, it was found out that Romney came in second place in the Iowa caucus and 16 days after the caucus it was made public that he had actually lost to Santorum by 34 votes.

Iowa caucus 2016: Roughly 182,000 Republican caucus-goers turned out for the 2016 Iowa caucuses, which was a record-breaking turnout for the primary event. The GOP race included Donald Trump, Sen. Ted Cruz and Sen. Marco Rubio. Cruz went on to win the caucus, receiving the most votes ever in the Hawkeye State for a single candidate, but Trump went on to become president.

This mishap affected the Republican Party in Iowa, forcing them to admit that there was a mistake in counting votes.