AI Election Model - 2028 Republican Presidential Primary [Week 6 - Aug. 28 Update]

Rubio gains buzz, DeSantis holds steady, and Vance keeps pulling away

Aug 28, 2025

This will be the last GOP update in August. It’s all back to the grind after this Labor Day holiday, which might bring us some new political twists.

Once again, here’s our weekly look at using general-purpose AI models, like ChatGPT and Gemini, to predict the 2028 GOP nominee and gather data along the way.

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This week’s average shows how four AI models (Grok, ChatGPT, Gemini, and Claude) rank the leading contenders for the 2028 Republican presidential nomination. The goal is to track these results over time and refine methods for using AI to forecast not only the GOP nominee but eventually the outcome of the 2028 general election.

AI Model Average - 2028 Republican Nomination (Aug. 28, 2025)

Vice President Vance, the clear and away frontrunner, has dropped almost seven points since last week, with several of the lower-tier candidates fighting over the scraps.

As usual, the Sunshine State battle between Ron DeSantis and Marco Rubio rages on.

AI Model Average - 2028 Republican Nomination (Aug. 28 vs. Aug. 22)

Here’s the comparison from our last run back on Aug. 22. You can see Vance’s lead dropping this week while DeSantis and Rubio remain practically the same.

Tulsi Gabbard, RFK Jr, and Kristi Noem have been bid farewell. Glenn Younking is now back in the mix after disappearing last week.

Individual Model Data

Finally, here’s the model breakdown with numbers from each platform this week. In the averages above, candidates not appearing in the top 5 for a given model are assigned a 0 for that model.

ChatGPT (Aug. 28)

40% - JD Vance
20% - Ron DeSantis
14% - Marco Rubio
12% - Glenn Youngkin
14% - Donald Trump Jr

Grok (Aug. 28)

45% - JD Vance
10% - Ron DeSantis
9% - Marco Rubio
7% - Nikki Haley
5% - Vivek Ramaswamy

Gemini (Aug. 28)

43% - JD Vance
9% - Ron DeSantis
7% - Marco Rubio
6% - Nikki Haley
4% - Vivek Ramaswamy

Claude (Aug. 28)

35% - JD Vance
15% - Marco Rubio
12% - Ron DeSantis
8% - Vivek Ramaswamy
6% - Ted Cruz

Analysis

Despite positive news out this week cementing Vance as the most likely Trump heir, his numbers took a hit. While it’s not easily discernible why this could be, it likely stems from the ebb and flow of summer news cycles, and without something concrete, our AI model panel is making an educated guess, which brought Vance’s numbers down a peg more in line with polls that see him topping around 40%.

So far, Vance has not surpassed 50% in our model, but that may happen at some point. Until then, polling averages currently see him around 47%, which is where he landed last week in our data.

For the foreseeable future, every mainstream news article on the 2028 GOP nominee is going to be focused on Vance while putting Rubio as a close second. DeSantis will be in the mix for a while, but after next year, when he’s term-limited out of Florida, his clout may wane. See former Wisconsin Gov. Scott Walker, for example.

Unless and until Vance does something that runs afoul of MAGA, he’s the one to beat and could conceivably end up clearing the field before the race even begins.

That’s all for this week. See you in September when we’ll pick back up next week.

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