He was not turned at the Point. He was essentially kicked out of the Ranger regiment for being a PIA - he was already a loudmouth socialist there.
He was certainly pushed along at The Point. http://www.breitbart.com/big-government/2017/09/28/exclusive-west-point-professor-who-mentored-antifa-soldier-on-administrative-leave/
At West Point, Hosein had mentored Rapone. The two apparently traveled together to India together in 2014 and maintained a close relationship until Rapone graduated in May 2016.
Also during that time, Rapone’s Facebook posts grew increasingly radical and leftist.
Rapone’s activities caught the attention of command authorities this week after he posted photos of himself in his West Point uniform while promoting communism on social media.
According to photos on Rapone’s Facebook page, he became close to Hosein, a Ph.D. in Islamic history from the University of Chicago. The two appear to have traveled together to the Taj Mahal in March 2014, according to pictures posted on his Facebook page.
On March 18, 2014, Hosein posted on his Facebook page, “Back from the Taj [Mahal] and it delivered.” Two days later, on March 20, 2014, Hosein posted a picture of himself, wearing a long tunic, and Rapone, wearing a turban and a long tunic, with the caption: “The brothers are gonna work it out.”
On March 23, 2014, Rapone posted about anti-corporatism and racism. On March 24, 2014, Rapone posted a picture of himself and Hosein in front of the Taj Mahal.
Later that year, on August 19, 2014, Rapone posted a picture that showed them in a classroom with another soldier. “The Intelligentsia,” the caption read. Hosein was tagged in the picture, suggesting they were Facebook friends at the time.
A review of Rapone’s Facebook page shows that over time, since 2014, his posts became increasingly anti-racism, anti-Israel, pro-Muslim, pro-Communist, anti-military, and anti-police.
On January 5, 2015, he posted a Slate.com article calling for the abolishment of West Point. As a Facebook friend since 2014, Hosein would have been aware of Rapone’s Facebook postings between 2014 and when he graduated in 2016. A search of Rapone’s page shows they are still Facebook friends.