Both Republican and Democrat Senate staff were surprised that President Trump's pick for Army secretary cleared White House and Pentagon vetting, according to the advocacy group Human Rights Campaign.

The visits to Senate offices were part of an opposition campaign by the LGBT advocacy group to Tennessee state Sen. Mark Green, which also included 6,800 phone calls this week to lawmakers in the chamber. It has been joined by 40 other civil rights groups.

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The nomination — still not formally sent to the Senate — appeared in jeopardy Friday after reports Green might not have enough support to be confirmed due to past comments about gay marriage, transgender rights and Islam. More opponents piled on, including Rep. Adam Smith, the top Democrat on the House Armed Services Committee, and 10 retired generals and admirals.

"Every office we've met with has been surprised, on both sides of the aisle, with the record that he has on these issues," said David Stacy, government affairs director for the Human Rights Campaign, an LGBT advocacy group. "So, we have had a high degree of concern, a lot of surprise from Hill staff that he cleared the White House vetting process or the Pentagon vetting process."

The Senate Armed Services Committee declined to comment Friday on Green.

When questioned about Green, a Pentagon spokesman said he had no comment.

The controversy has been sparked by public YouTube videos and recorded interviews of Green, a devout Christian and former Army flight surgeon, made over the past few years that show him telling audiences that most psychiatrists believe being transgender is a disease, Tennessee should reject the Supreme Court ruling on same-sex marriage, teaching Islam in public schools in unacceptable, and that public healthcare is unjust because it keeps churches from converting people to Christianity.

Trump announced Green's nomination one month ago and it sparked opposition from the Human Rights Campaign as well as a few other civil rights groups almost immediately.

The controversy has been snowballing this week, with top Democrats in the Senate and House saying Green is unfit to be the Army's top civilian.

On Friday, 41 groups including the Human Rights Campaign signed a letter to Sens. John McCain and Jack Reed, the top Republican and Democrat on the Armed Services Committee.