The Republican National Committee's former Hispanic outreach director in Florida has become a Democrat, citing the Republican party's "intolerance" and a general frustration with the party's attitude toward immigration.

Pablo Pantoja wrote in an e-mail to supporters on Monday that "it doesn’t take much to see the culture of intolerance surrounding the Republican Party today."

"I have wondered before about the seemingly harsh undertones about immigrants and others," he said. "Look no further; a well-known organization recently confirms the intolerance of that which seems different or strange to them."

Without naming him, Pantoja alluded to Jason Richwine, the co-author of a Heritage Foundation report on the costs of immigration reform. Richwine resigned from the think tank last week amid revelations about his past, including that he wrote in his dissertation that "no one knows whether Hispanics will ever reach IQ parity with whites, but the prediction that new Hispanic immigrants will have low-IQ children and grandchildren is difficult to argue against.”

Conservatives including Sen. Marco Rubio (R-Fla.) pushed back hard against the Heritage study. When pressed about why he would leave a party that includes prominent pro-immigration voices, Pantoja said in an e-mail to Post Politics that such support is not being given its due.

"Those voices and stances are not being well taken," he said. "Studies like the recent one behind the immigration debate are part of that culture of intolerance. Everyone has to make their own decision and I wouldn't consider they would change over this necessarily. Fortunately, I feel like I am in a private and personal position where I can do that."

Pantoja, who was born and raised in Puerto Rico, worked as the RNC's Florida Hispanic outreach director before leaving the organization last summer. A Republican strategist described a strained relationship between Pantoja and the committee, and said that after he left the RNC, Pantoja sought out work at both the RNC and the Republican Party of Florida.

Pantoja declined to discuss his work at the RNC but didn't deny the claims that he had sought out employment with Republican groups after leaving his position.

-- Rachel Weiner contributed to this post