Top White House aide, after abuse allegations from his two ex-wives were made public. The White House was made aware of the allegations in November and allowed him to work without a full security clearance, CBS News' chief White House correspondent Major Garrett reports.
White House communications director Hope Hicks, who is dating Porter, helped craft his public statement, Garrett confirmed.
"My commitment to public service speaks for itself," Porter, who has denied the allegations, told reporters in a statement. "I have always put duty to country first and treated others with respect. I am deeply grateful for the opportunity to have served in the Trump administration and will seek to ensure a smooth transition when I leave the White House."
A federal law enforcement source confirmed to CBS News' Jeff Pegues that the FBI conducted a background check on Porter and knew of the allegations levied against him by his two-ex wives. That information was passed on to the White House. The White House staff secretary -- who has access to and reviews presidential correspondence -- never received full security clearance, and the allegations were the main reason why, two sources tell Garrett.
White House press secretary Sarah Sanders, who refused to comment on Porter's security clearance status to Garrett from the briefing room podium Wednesday, said Porter would not be leaving immediately to ensure a smooth transition. Sanders claimed she has not asked the president's opinion of the allegations against his staff secretary. Porter, according to White House salary disclosures, earns the highest salary level in the White House -- $179,700. Porter is dating White House communications director Hope Hicks, CBS News has confirmed.
It's possible Porter was conducting his job on a temporary clearance. A former Obama official told CBS News it would be difficult to conduct Porter's job without a security clearance.
"I don't know how you would do that job without a security clearance," the former official said. "You see every single piece of paper -- whether it's from the NSC or from specific Cabinet secretaries. You have to have the highest clearance, across the board. You read every single thing, to make sure it's ready for the president, to make sure the necessary principles have weighed in.
"You see the president countless times each day, travel everywhere with him," the former official added. "I don't know how anyone could be in that job without a security clearance, unless it is constructed very differently in the Trump administration."
The Daily Mail first reported the allegations against Porter. Porter's first ex-wife, Colbie Holderness, provided an image to the Daily Mail showing her with a black eye -- which she alleged resulted from Porter punching her on vacation in Florence, Italy, in the early 2000s. According to the Daily Mail, the two Mormons met at church in 2000.
Holderness also told the Daily Mail that Porter would also kick and berate her about her weight. And his violent behavior grew in intensity. Porter, she said, even choked her.
"It was not hard enough for me to pass out but it was scary, humiliating and dehumanizing," Holderness told the Daily Mail.
CBS News spoke with Jenny Willoughby, Porter's second wife. Willoughby said the FBI asked her standard questions about possible domestic violence, in the context of Porter's security clearance. Willoughby said she is issuing a joint statement with Holderness concerning Porter, "because we want to have a unified front," she said.
CBS News' Laura Strickler obtained the emergency protective order Willoughby filed on June 23, 2010, in Arlington General District Court after Porter allegedly violated their separation agreement, refused to leave the Northern Virginia apartment and punched out the glass on the door, cutting his hand. The protective order was granted for four days in June 2010.
The emergency protective order gives the following account from Willoughby at the time:
"Rob was angered last night when I asked him to leave my apartment based on his violation of our private separation agreement. He would not leave for over 30 minutes claiming he lost his keys. When I found the keys and gave them to him he stayed on the porch and would not leave for another 10-15 minutes until I threatened to call the police. Today, (Saturday, 6/19/2010) he returned to my apartment and let himself in with a key that I have requested back. (Requested in the presence of our church clergy last Sunday 6/13/10) When I asked him why he was there he said to get his clothes. He wanted to hug and make up but was angry when I asked that he get his things and leave. I asked him several times to leave with his things but he did not until I picked up the phone to call our clergy member. While he was gone, I took his clothes and put them in a suitcase on the front porch. When he returned a few minutes later, he punched in the glass on the door. I called the police, afraid he would break in. He came to the door asking me to let him in to take him to get medical attention. When he heard me on the phone with the police he apologized and begged me not to involve them. When he heard me give my name and address to the 9-1-1 dispatcher he drove off."
The FBI is referring all questions concerning Porter to the White House.
The Daily Mail published a comment from White House chief of staff John Kelly praising Porter, in response to the allegations.
"Rob Porter is a man of true integrity and honor and I can't say enough good things about him," The Daily Mail published Kelly as saying. "He is a friend, a confidante and a trusted professional. I am proud to serve alongside him."
So did Sanders.
"I have worked directly with Rob Porter nearly every day for the last year and the person I know is someone of the highest integrity and exemplary character," the Daily Mail quoted Sanders as saying.
Late Wednesday, Kelly told reporters he stood by his earlier comments that Porter is "a man of integrity and honor."
"I was shocked by the new allegations released today against Rob Porter," Kelly said. "There is no place for domestic violence in our society. I stand by my previous comments of the Rob Porter that I have come to know since becoming chief of staff, and believe every individual deserves the right to defend their reputation. I accepted his resignation earlier today, and will ensure a swift and orderly transition."
Before joining the White House, Porter worked for Sen., who is retiring from the Senate. Hatch, who on Tuesday issued a statement defending Porter and calling the reporting on him politically motivated, issued another statement on Wednesday.
"I am heartbroken by today's allegations," Hatch said. "In every interaction I've had with Rob, he has been courteous, professional and respectful. My staff loved him and he was a trusted adviser. I don't know the details of Rob's personal life. Domestic violence in any form is abhorrent and unacceptable. I am praying for Rob and those involved."
An aide to Hatch told CBS News, "Before the accusations were printed, Senator Hatch had been informed by multiple sources that there was a coordinated effort underway to smear and undermine Rob. His comment was not related to the women or their accounts, he made it before any stories were written."
Reporters caught up with Hatch on Capitol Hill later Wendesday and asked him about reports that he had encouraged Porter not to resign.
"I encouraged him to keep a stiff upper lip and work out his problems," Hatch said. "And I would prefer him not to resign, just work his way through and do what's right." The Utah senator called Porter a "very talented guy" and added, "I don't want to see him lose it."
He went on to say that Porter had done "a tremendous job" for him, and "if I could find more people like him, I would hire them."
"I think that's how good he is," Hatch continued. "And he's basically a good person."
CBS News' Alex Derosier and Alan He contributed to this report.