Former President Donald Trump secured a resounding victory in the Iowa caucuses, demonstrating the strong support he has garnered within the Republican Party over the past eight years. Trump outperformed his 2016 caucus results, winning almost every county in Iowa and 87 percent of precincts, leaving his closest rivals, Florida Gov. Ron DeSantis and former South Carolina Gov. Nikki Haley, trailing by more than 30 points.

However, Trump's hold on the GOP electorate was not absolute, as nearly half of the voters, 49 percent, chose to back alternative candidates. A closer analysis of precinct-level results and entrance polls conducted by POLITICO revealed a notable weakness for Trump in suburban and urban areas. In numerous suburban precincts, Trump received less than 25 percent of the vote, compared to his overwhelming victories in rural precincts where he obtained over 90 percent of the votes. This pattern has troubled Republicans in recent elections.

While Trump has successfully consolidated the majority of Republican support, the data also highlights his vulnerability among suburban and highly educated voters. This raises concerns about how he plans to win over this voting bloc, which has historically viewed him with skepticism and played a role in his 2020 loss.

Despite facing challenges from other candidates, Trump outperformed his previous Iowa caucus results across the state. In areas where he was previously weakest, the former president made significant gains. Several dozen precincts that gave him less than 10 percent of the vote in the 2016 caucuses saw him win 35 percent of the vote this time around.

Traditional Republican strongholds, such as Sioux County, which had favored candidates like Sen. Ted Cruz and Sen. Marco Rubio in 2016, also showed a shift in support towards Trump. In Sioux County, where Trump had only received 11 percent of the vote in 2016, he decisively won with 45 percent in this year's caucus.

Trump maintained his strongholds and even improved his support in areas where he had performed well previously. For example, in Fremont County, Trump won 42 percent of the vote in 2016 and increased that to 68 percent this year.

While Trump's performance solidifies his frontrunner status within the GOP, the fact that almost half of caucusgoers chose alternative candidates indicates a desire for an alternative to Trump within the party. The votes of these individuals were mainly concentrated in suburban and urban areas, suggesting that voters in these regions remain wary of Trump. This group includes those with higher education levels, a demographic that proved costly for Trump in the 2020 election and has been challenging for Republicans in general.

Trump's only defeat came in Johnson County, home to the University of Iowa, where former Ambassador to the United Nations Nikki Haley edged him out by a single vote. Trump also struggled in Ames, the location of Iowa State University, winning just 27 percent of the vote across the city's 22 precincts.

Furthermore, Trump performed worse in areas where he fell short of President Joe Biden in the 2020 presidential election. These areas tend to have more moderate Republican and independent voters. Out of the six counties that Biden won in Iowa, Trump only managed to exceed 50 percent of the vote in Black Hawk County.

Entrance polls conducted during the caucuses reveal a divide by educational attainment, mirroring national trends. While Trump made significant gains among Republican caucusgoers without college degrees, winning the support of 67 percent of them, he only secured 37 percent of the vote among those with college degrees.

Additionally, Trump made notable gains among older caucusgoers, but failed to generate substantial interest among younger voters. Counter to some public polling during the general election, there was no surge of support for Trump among young voters in Iowa.

The Iowa caucuses have illuminated the strength and weaknesses of Trump's support within the Republican Party. While he has united a majority of Republicans, his vulnerabilities among suburban and highly educated voters will require strategic efforts to win their trust and support.