Using his personal Twitter profile instead of making an official statement, President Donald Trump abruptly announced Wednesday that he would reverse the Obama administration’s decision to allow transgender people to serve in the military. Arguing that the military cannot afford the extra spending on medical care—in reality, health-care expenses associated with transgender troops only cost the military between $2.4 million and $8.4 million annually—Trump cited unnamed generals and military experts, saying that not allowing transgender people to serve is necessary for “victory.”

“After consultation with my Generals and military experts, please be advised that the United States Government will not accept or allow transgender individuals to serve in any capacity in the U.S. Military,” Trump wrote in a series of tweets. “Our military must be focused on decisive and overwhelming victory and cannot be burdened with the tremendous medical costs and disruption that transgender in the military would entail. Thank you.”

The decree from Trump, who himself avoided serving in Vietnam after receiving a medical deferment for heel spurs, seemed to stun military leaders and civilians alike. The Associated Press reported that the Pentagon seemed unaware of the president’s decision, refusing to answer questions about the new policy and referring all questions to the White House. Secretary of Defense James Mattis is currently on vacation. And the Senate Armed Services Committee, which oversees the nation’s military, was not briefed beforehand. Senator John McCain, who chairs the committee, released a statement condemning the decision and ripping Trump for making policy announcements over Twitter.

It remains unclear how the edict, which would stop the U.S. military from accepting transgender troops into its ranks or allowing them to serve in any capacity, would affect the estimated 6,000 transgender troops who are already serving. A report from the nonpartisan RAND Corporation in 2016 found that transgender troop inclusion would not have a material effect on troops’ readiness to fight. Then again, a percipient analysis of the potential pros and cons of Obama’s transgender policy, or of the consequences of reversing it, does not appear to have been front of mind for the White House. “This forces Democrats in Rust Belt states like Ohio, Michigan, and Wisconsin, to take complete ownership of this issue,” one administration official told Axios’s Jonathan Swan, explaining their thinking. “How will the blue-collar voters in these states respond when senators up for re-election in 2018 like Debbie Stabenow are forced to make their opposition to this a key plank of their campaigns?”

According to The Washington Post’s Greg Sargent, Democrats are not actually worried that fighting Trump’s transgender-troop ban will hurt their electoral prospects next year. In fact, the backlash online seemed to be mostly bipartisan in the wake of the president’s announcement.

Many pointed out that Trump and his daughter Ivanka had both talked up their support for the LGBT community in the ‘90s, during the 2016 presidential campaign, and as recently as a few months ago.

Others were confused about why Mattis didn’t make the announcement.