His former wives recounted physical, verbal and emotional abuse they say he subjected them to during their marriages.
John Kelly, the White House chief of staff, publicly praised Porter after the abuse allegations emerged and reportedly kept him on even though the Federal Bureau of Investigation denied the staffer a security clearance.
Colbie Holderness, Porter's first wife, said he punched her once in the face while they were on vacation in Italy in 2005, leaving a massive bruise shown in the pictures.
Kelly continued to press him to stay in his job Wednesday, saying he could weather the storm, but Porter decided the controversy had become too much after the damaging photos of the blackened eye appeared Wednesday morning. Orrin Hatch, R-Utah. Although many of his colleagues have eclectic backgrounds, Porter boasts a classic pedigree as a Harvard-educates Rhodes scholar whose father, Roger Porter, held senior positions in the Ronald Reagan and George H.W. Bush White Houses.
"Rob was abusive, degrading, a liar and a cheater and during the course of my relationship with him, I found out that he was to others, too", the woman wrote to Willoughby in February 2016. "The country needs more honest, principled people like Rob Porter, which is why I hope that this cynical campaign to discredit his character ultimately fails". "He graduated to choking me, not ever hard enough to make me pass out, or frankly to leave marks, but it was frightening and dehumanizing".
Trump's desk, including the wave of executive orders and actions that Trump inked during the first months of his tenure.
When John Kelly replaced Reince Priebus as White House chief of staff, Porter's role expanded.
Porter added that he was grateful for the opportunity to serve in the Trump administration. Hatch's office provided the statement to the White House - at its request - before the Daily Mail story was published.
After Scaramucci came White House adviser Sebastian Gorka, farthest left, who claimed he resigned from the White House in late August, while other officials said he was essentially fired from his job.
"There is no place for domestic violence in our society".
Both Willoughby and Holderness said they told the Federal Bureau of Investigation about Porter's conduct and were dismayed to learn of his senior role in the White House.
"When Sen. Hatch spoke to Rob at the White House today, the two discussed his next steps and Sen". Porter said photos published of his former spouses were taken almost 15 years ago and do not tell the complete story. "And I would prefer him not to resign, just work his way through and do what's right".
His influence growing in recent months, Mr Porter was often seen with Mr Trump when the President travelled and as he signed legislation or proclamations.
A person familiar with West Wing dynamics said Porter has expressed interest in an elevated policy role over the past weeks.