Hillary Clinton's recent lead in the polls has many doubting Donald Trump's ability to win the upcoming election, but a leaked email reported by financial blog Zero Hedge shows Democrats using "oversampling" to inflate polling numbers.

The email, sent in 2008 by Democratic activist Tom Matzzie, reads:

"I also want to get your Atlas folks to recommend oversamples for our polling before we start in February. By market, regions, etc. I want to get this all compiled into one set of recommendations so we can maximize what we get out of our media polling."

According to Zero Hedge's anonymous writer, who uses the site's shared pen name Tyler Durden, "That's how you manufacture a 12-point lead for your chosen candidate and effectively chill the vote of your opposition."

Trump himself tweeted about the story Monday morning, although he did not attribute it to Zero Hedge or include a link to their article.

Major story that the Dems are making up phony polls in order to suppress the the Trump . We are going to WIN! — Donald J. Trump (@realDonaldTrump) October 24, 2016

However, The Washington Post denies Zero Hedge's interpretation, arguing that Matzzie wasn't talking about public polls, since those are handled by independent pollsters working with media outlets. Instead, they presume Matzzie was referring to internal polling done to inform media buys.

"In other words, before campaigns spend $200,000 on a flight of TV spots, they'll poll on the messages in those ads and figure out what to say to whom and then target that ad to those people as best they can," writes the Post's Philip Bump.

"The problem is that it can be hard to find enough people to get robust enough sample sizes to offer the necessary information," he continues.

"Normal polling in a state will usually have no problem getting enough white people in the mix to evaluate where they stand, but you may need to specifically target more black or Hispanic voters to get a statistically relevant sample size."

According to the Post, campaigns often oversample, meaning intentionally including more members of a certain group in sampling, to "figure out how to craft a message" tailored to those groups.