Political ad spending in the 2016 election cycle is forecast to eclipse $10 billion, driven by Super Pacs and saturated placements in swing states like Ohio, Florida and Virginia. Millions more will be spent on polling – although one playful metric involving ad specialties might be the best predictor of all. Online retailer CafePress has unveiled an Election Barometer that keeps tabs on the popularity of candidates based on the sales of their related logoed products.

Donald Trump is the clear leader among Republicans, as CafePress has sold more than 26,000 Trump-branded products so far this cycle. On the Democratic side, Bernie Sanders has recently pulled ahead of Hillary Clinton by a 19,132 to 17,276 margin. On its barometer page, CafePress says it has “correctly predicted past presidential elections based on sales data alone.” You can view the Barometer by clicking here.

CafePress is selling both pre-made and customizable campaign designs that fit on shirts, mugs, buttons, bumper stickers, magnets and several other items. The site allows shoppers to view items based on candidate preference, party affiliation and key election issues, like immigration and healthcare reform.

While slogans like “Feel The Bern” are popular on CafePress, one motto is noticeably absent. Donald Trump’s tagline “Make America Great Again” was recently removed from the site after the candidate sent a cease and desist letter to the retailer claiming he owns the trademark rights to his slogan. Other mottos, though, like “Hair to the Chief” remain.  

CafePress says its Election Barometer will be updated with sales data each week leading up to the 2016 presidential election.