Likely Republican presidential candidate Jeb Bush criticized the Democrats’ Hillary Clinton on Wednesday for apparently backpedaling on a trade agreement that has split her party.

Bush, the former Florida governor and brother and son of former presidents, pointed out in an article published at Medium that Clinton supported the Trans Pacific Partnership when she was Barack Obama’s secretary of state between 2009 and 2013. Now, as she is a candidate to succeed Obama, she believes trade agreements “have to pass fresh tests and even greater scrutiny,” according to Bush.

The Republican, who hasn’t formally announced his own candidacy, strongly backed the trade pact, arguing it would contribute to “the sustained, high rate of growth that we need to create well-paying jobs.”

We’ve worked with some of our most important allies in negotiations to help make this possible – and asked them to take political risks of their own to open their markets to American goods, agricultural products and services. It sends a terrible signal this late in the negotiations for Secretary Clinton to pull the rug out from under our allies for a short-term political gain.

Free trade isn’t especially popular on the left. Progressives, led by Massachusetts senator Elizabeth Warren, refuse to give President Obama the negotiating authority he needs to get the trade agreement done.

“When giant corporations get to see the details and the American people don’t, we all lose,” Warren wrote on her website on Wednesday.

A day earlier, the president told MNSBC Warren was “wrong” on the issue. “I would not be doing this trade deal if I did not think it was good for the middle class,” he said.

Many Democrats nevertheless fear freer trade will undercut wages in the United States and ship more jobs overseas.

Among Warren’s allies are the two most powerful Democrats in the Senate: Harry Reid, the retiring minority leader, and Chuck Schumer, his likely successor.

Most Republicans, who are traditionally more friendly to business, favor the trade pact but they are wary of giving Obama so-called fast track authority to get the deal done.

Fast track would allow the administration to negotiate a treaty and then present it to Congress for a yes-or-no vote. Without such authority, partners in East Asia and Latin America could be reluctant to make concessions when lawmakers in the United States could at any point derail the talks.

The Trans Pacific Partnership would lower trade barriers for twelve nations on the Pacific that jointly account for 40 percent of the world’s commerce.

It is more than a trade agreement. The pact is also part of Obama’s “rebalancing” strategy, designing to bring China into the existing liberal world order rather than have it attempt to create a competing, presumably more authoritarian, order under its own leadership. China isn’t part of the talks. But a successful treaty would pressure the country — which is expected to overtake America as the world’s largest economy within the next few years — to meet its standards and stop trying to game global trade to impede foreign companies.