Pro-trade Republicans are on uneven ground in the 2016 campaign, caught between past support for free-trade deals and the vocal opposition to those agreements that helped propel Donald Trump to the Republican presidential nomination.

The dilemma has caused some Republicans to rethink their positions on trade, with several vulnerable senators up for re-election and other GOP lawmakers coming out against the 11-nation Trans-Pacific Partnership, all but guaranteeing the agreement won’t pass Congress this year.

Florida Sen. Marco Rubio, who is running for re-election after being one of more than a dozen Republicans who lost to Trump in the presidential primary, is generally for free trade, but has yet to make a decision on the merits of the TPP.

But in a sign of how volatile the issue is in 2016, Rubio’s campaign removed the section of his website about his support for fast-tracking trade agreements in Congress and the timely adoption of new deals when the site was revamped for his Senate race.

The infrastructure of Rubio’s Senate race website is vastly different from the presidential campaign version, including a different layout and fewer specific policies highlighted on the issues page. In the section labeled “Farmers and Ranchers,” however, the policies are nearly word-for-word identical to those on his former site, from urging repeal of regulations to opposing the estate tax and energy taxes. The only significant difference is that a section promoting his pro-trade stance has been completely removed.

“Marco supports Trade Promotion Authority (TPA), which asserts Congress’s role in critical trade negotiations and paves the way for the creation of agricultural jobs. Marco will also push for timely completion of trade agreements to boost exports for American farmers and ranchers,” the same section read on his presidential website, accessed under Internet archives pages.

TPA, also known as fast track authority, is a process to allow swifter adoption of trade agreements in Congress with an up-or-down vote without the deals being amended. It paved the way for the Trans-Pacific Partnership, which was completed last year. But the agreement has yet to be submitted to Congress and is unlikely to pass this year, if at all, because of significant opposition in both parties -- fueled in part by the opposition of both presidential candidates, Donald Trump and Hillary Clinton.

Clinton came out against TPP early in her presidential bid after intense pressure from progressives -- aided by the surprising success of Sen. Bernie Sanders’ campaign message opposing the agreement. While secretary of state, however, Clinton had praised it as the “gold standard.”

In something akin to Rubio’s website change, Clinton’s autobiography about her time as the nation’s top diplomat originally included references to her work on TPP, but the paperback edition, released this summer, had removed those references.

Rubio – along with a number of lawmakers on both sides of the aisle – has not yet made a decision on TPP. Two pro-trade Republicans in competitive Senate races, however, have voiced their opposition to it: Ohio Sen. Rob Portman and Pennsylvania Sen. Pat Toomey, who announced his stance this week.

Rubio told Politico in May he was meeting with groups on both sides of the issue before coming to a decision.

“I’m in favor of free trade, but it has to be the right deal,” Rubio said at the time. “And if this is not the right one, it should be renegotiated. Whether a President Trump or President Clinton would do so, if you take them at their word in terms of what they’ve said on the campaign trail, it doesn’t look like it.”

Rubio campaign spokeswoman Olivia Perez-Cubas said that the senator’s positions on TPA and the TPP have not changed.