Sens. Bernie Sanders and Elizabeth Warren are two of Amazon's most outspoken critics, each having pledged to break up the e-commerce giant if they become president in 2020.

But a recent analysis of campaign expenditures in the second quarter of 2019 found that both Sanders' and Warren's presidential campaigns spent far more at Amazon than any of the other Democrats in the race.

Visit BusinessInsider.com for more stories.

Sens. Elizabeth Warren of Massachusetts and Bernie Sanders of Vermont are two of Amazon's most outspoken critics, each repeatedly vowing to break up the tech company if they get their wish and unseat President Donald Trump in 2020.

But Sanders and Warren both have another thing in common as it relates to Amazon: their presidential campaigns spent more money at the e-commerce giant than anyone else in the Democratic field.

Read more: Beto O'Rourke rejects Elizabeth Warren's plan to break up Amazon

According to an analysis by the Washington Free Beacon, which examined 21 Democratic presidential campaigns' spending habits at Amazon through their Federal Election Commission reports released at the end of the second quarter of 2019, Sanders outspent everyone by almost $100,000, with Warren not far behind.

The analysis found that from April to July of this year, Sanders' campaign spent $138,148 on Amazon goods and services. Warren's campaign came in second by spending $51,990. New Jersey Sen. Cory Booker's campaign spent $31,366 as well. No other campaign spent more than $6,000 at Amazon.

Warren became the first candidate to introduce a policy proposal that would break up Amazon, separating Amazon's different departments and assets into different companies, including Whole Foods, Amazon Marketplace, and more.

"Amazon crushes small companies by copying the goods they sell on the Amazon Marketplace and then selling its own branded version," Warren wrote in a Medium post detailing the plan.

Sanders has been one of the more vocal critics of Amazon during his tenure in the Senate, introducing bills like the "Stop Bezos Act" and regularly criticizing their labor practices. Sanders also frequently targets Amazon for what he characterizes as unfair wages.

"If Amazon, Walmart and other corporations won't pay their workers a living wage, our bill would establish a 100 percent tax equal to the amount of federal benefits received by their low-wage workers," Sanders said in 2018. "The American taxpayer should not be subsidizing the richest people in history so they can underpay their employees."