Ever since Senate Majority Leader Mitch McConnell successfully mounted a campaign to block witness testimony in President Donald Trump’s impeachment trial, it’s been taken as a foregone conclusion that Trump will be found innocent.

That hasn’t exactly changed, but Senator Mitt Romney issued a surprise announcement on Wednesday, saying his faith has motivated him to vote to convict Trump. He is the first Republican to do so.

“I am profoundly religious,” Romney said. “My faith is at the heart of who I am.”

Romney noted that he has been broadly supportive of Trump’s policies (he voted with him 80 percent of the time) but could not use that as an excuse to find him innocent. “My promise before God to imply impartial justice required that I put my personal feelings and political biases aside,” Romney said.

“Were I to ignore the evidence that has been presented and disregard what I believe my oath and the Constitution demands of me for the sake of a partisan end it would, I fear, expose my character to history’s rebuke and the censure of my own conscience.”

Romney acknowledged that his vote would make him the target of Trump’s infamous wrath and the scorn of many in his own party. He also says he realizes that his vote may make little difference (at least 20 Republicans would have to vote to convict Trump for him to be removed from office). “Does anyone seriously believe that I would consent to these consequences other than from an inescapable conviction that my oath before God demanded it of me?” Romney asked.

Reports say Romney’s announcement caught Trump’s team by surprise since it throws a wrench into the White House’s message that the impeachment is a nakedly partisan farce.

“I will only be one name among many — no more, no less — to future generations who look at the record of this trial. They will note merely that I was among the senators who determined that what the President did was wrong. Grievously wrong.”

“We are all footnotes at best in the annals of history,” said Romney in closing. “But in the most powerful nation on earth – the nation conceived in liberty and justice – that distinction is enough for any citizen.”

You can watch Romney’s whole speech below.

Romney is a Mormon. In 2007, he addressed his religion in a speech called “Faith in America”, in which he addressed his beliefs. “What do I believe about Jesus Christ? I believe that Jesus Christ is the Son of God and the Savior of mankind,” Romney said. “My church’s beliefs about Christ may not all be the same as those of other faiths. Each religion has its own unique doctrines and history. These are not bases for criticism but rather a test of our tolerance. Religious tolerance would be a shallow principle indeed if it were reserved only for faiths with which we agree.”