There’s also the distinct chance that the campaign in Washington could go the way of other recent issues, such as punitive measures against Russia and Saudi Arabia, that also had strong bipartisan backing in Congress only to be hollowed out when they reached the executive branch.

Rubio said he has personally spoken with Trump about the bill and has not encountered resistance. “The White House has indicated that they would sign it,” he noted.

Yet as Trump’s former consul general to Hong Kong and Macau has observed, Hong Kong is a “second-tier” matter in the administration relative to, say, trade with China and addressing the nuclear threats from North Korea and Iran. Trump has mostly been silent on Hong Kong. When he has mentioned it, he has explicitly linked the issues of trade and Hong Kong (even as his advisers dismiss any connection), warning the Chinese government that violent suppression of the protests would jeopardize trade talks and arguing that this threat is precisely what has restrained Beijing so far. At times Trump has appeared to take China’s side, such as when he described the demonstrations as “riots.” Occasionally he has said he’s in favor of Hong Kong’s freedom. More often he’s suggested that the Chinese leader, Xi Jinping, meet with protesters, an idea Xi hasn’t shown the faintest indication of entertaining.

Rubio said he didn’t believe Trump would veto the legislation to placate the Chinese as trade talks resume, noting that he thinks the bill will pass with a veto-proof majority. (The Trump administration has made such moves in the past, such as when it reportedly postponed a tough speech on China by Vice President Mike Pence ahead of trade talks between Trump and Xi at the G20 summit in June.)

“I think the bigger concern is in its implementation,” Rubio said. “You can pass the bill, but it still requires the administration to implement it. It still requires them to conduct the annual review and it still requires them to impose sanctions on individuals, for example, police officials responsible for repression. They could theoretically sign the bill—them or a future administration —and yet not implement it.”

Rubio added that he has made the argument to Trump “that if the Chinese are prepared to break the commitments they made on Hong Kong [as part of a 1984 agreement with Britain on transferring control of the territory to China], how could we trust them to keep any commitments they make on trade or any other matter?”

Read: Hong Kong’s protests have cemented its identity

In Hong Kong, meanwhile, the bill is being championed by pro-democracy lawmakers and activists who have recently made trips to Washington to lobby for its passage, angering both pro-establishment figures in the territory and officials in Beijing.

China’s oversight of Hong Kong has taken a “serious deviation from the original intent of ‘one country, two systems,’” Dennis Kwok, a member of the city’s Legislative Council, told The Atlantic, referring to the framework under which Hong Kong has operated since 1997, when the territory was handed back to China. In August, Kwok and other Hong Kong lawmakers traveled to meet with U.S. counterparts in Montana, where the nonprofit that organized the delegation has an office.