Carrie Fisher has a theory about why Donald Trump has been sniffling so much at the presidential debate.

Trump could once again be heard sniffling during the second presidential debate Sunday night, an encore of the sharp inhalation noises viewers noticed during the first presidential debate on Sep. 26. Fischer, of "Star Wars" fame, spent the night tweeting her reactions to the debate. Among her observations, Fisher responded to one fan's query about Trump's sniffling with an assertion that the noises were related to cocaine use. 

"Tell me something about that sniffle…coke head or no?" asked the fan.

"I’m an expert & ABSOLUTELY," replied Fisher, adding the all-caps emphasis. 

Fisher has admitted to having been a heavy cocaine user in the 1980s. Sniffling, like the kind heard from Trump Sunday night, can be symptomatic of the damage done by frequent use of cocaine via snorting and inhalation through the nose. 

Fisher's accusations that cocaine use is behind Trump's sniffling is speculative — there is no credible evidence that Trump has ever used the drug. However, she is not the first to make the claim. 

Former Vermont Gov. Howard Dean drew criticism after the first debate for insinuating on Twitter that Donald Trump used cocaine. "Notice Trump sniffing all the time. Coke user?" Dean asked. Dean, a doctor, refused to apologize for the comment, saying that, while he was in no position to diagnose Trump from afar, that sniffing is "a signature of people who use cocaine."

HBO's "Real Time" host Bill Maher also chimed in. 

"Hillary got a big bump after the debate. And it looked like Trump did a big bump before the debate," Maher said on his show. "A lot of people are saying it! He was sniffling a lot. Either that or he's allergic to facts."

Trump blamed the audible sniffling from the first debate on a faulty microphone.

"They gave me a defective mic. Did you notice that? My mic was defective within the room," Trump told reporters after the debate. "I wonder, was that on purpose? Was that on purpose? But I had a mic that didn't work properly."

Donald Trump Donald Trump could be heard sniffling at the first two presidential debates. Photo: Getty Images

The Commission on Presidential Debates appeared to support the GOP nominee's claim. 

"Regarding the first debate, there were issues regarding Donald Trump's audio that affected the sound level in the debate hall," the commission said.

Trump later clarified that the issue was the sound levels and not the mic itself. 

"We had a guy inside the room, oscillating my mic. It wasn't that the mic didn't work," Trump said. "Unfortunately, when I went to talk, they turned the mic up and down. So, we had a real problem."

Whatever issue may have been present in the first debate, viewers noticed the exact same sniffling sound again on Sunday. 

While Fisher might be being presumptuous in her cocaine accusations, it appears the sniffling noises are not just a mic issue.