Days earlier, former Secretary of State Hillary Clinton accused Gabbard of being a Russian asset.
According to Amash, Clinton is actually the asset -- President Donald Trump's asset.
"The thing we know for sure is that Hillary Clinton is a Donald Trump asset," he wrote.
The Michigan representative said that the 2016 Democratic nominee's attacks drive potential voters away, pushing them toward Trump.
"Hillary does -- and did -- drive many people into the arms of Donald Trump. Her attack on Tulsi does likewise," Amash said.
In his district, Amash explained, Trump gathered less votes than any Republican in modern times, and still managed to beat Clinton, because Democratic voters rejected her as a candidate.
"When I heard Hillary's remarks, I knew exactly what the right would say: The left smears anyone they don't like," he wrote.
Amash concluded the series of tweets with a message for Democrats.
The Michigan congressman said that claims such as Clinton's de-legitimize real concerns about Trump's connections with Russia, helping the president make the claim that the entire premise of special counsel Robert Mueller's investigation was nothing but a "hoax."
"Recognize that this plays right into Trump's hands; that it diminishes the legitimate inquiry into Russia; that it bolsters Trump's 'hoax' nonsense."
The former secretary of state said that the Hawaii representative is being "groomed" by Russia to run as a third-pary candidate and spoil the 2020 presidential election, helping Trump win again.
Amash is not the first prominent public figure to disagree with Clinton.