With Donald Trump in Europe ahead of the G7 summit in Sicily, 40 U.S. senators led by Minority Leader Charles Schumer (D-NY) are urging the White House to keep the United States in the Paris agreement.

“Backing out of the Paris Agreement now, after the years of painstaking negotiations and strong U.S. leadership it took to get the world to this point, would be a self-inflicted injury to America’s credibility and influence on the world stage,” they wrote in a letter released Tuesday.

“Imagine that: Donald Trump, who campaigned repeatedly that China was eating our lunch and taking our jobs, is willing to cede both economic and moral ground to China,” Schumer said.

By withdrawing from the historic accord, “we would be joining Syria and Nicaragua,” added Sen. Tom Carper (D-DE). “That’s not pleasant company for us to be in in regards to this issue.”

Not to be outdone (by much), 20 Republican senators led by Majority Leader Mitch McConnell (R-KY) came back with a missive of their own, inaccurately decrying the “burdensome regulations” that would come with Paris implementation.

“We applaud you for your ongoing efforts to reduce overregulation in America,” they told Trump, in text prepared by climate denier James Inhofe (R-OK) and Senate Energy and Public Works Committee Chair John Barrasso (R-WY). “To continue on this path, we urge you to make a clean exit from the Paris agreement so that your administration can follow through on its commitment to rescind the Clean Power Plan.”

Forces supportive of the U.S. staying in Paris got a boost Tuesday from Pope Francis, who urged Trump to stick with the agreement during the former reality TV star’s visit to the Vatican. “Francis gave the U.S. president a copy of his 2015 encyclical calling for urgent, drastic cuts in fossil-fuel emissions after a half-hour meeting in his private study,” Bloomberg reported. “Francis’s choice of gift suggests he is adding his voice to those pressing Trump not to renege on the Paris accord.”

Francis presented Trump with a copy of Laudato Si’ (Praise Be), the landmark, 180-page encyclical he released in 2015, and Trump improbably promised to read it.

“He is something,” Trump said, after his meeting with the pontiff.

But while the pro-Paris pressure on the White House has been amping up (continually, endlessly, in the face of a serially postponed decision), some voices are suggesting it’s just as well if the U.S. gets out of the way, rather than spending the next four years obstructing international climate progress.

“If the United States remains at the table, negotiations in the years to come could be significantly more contentious,” writes Matthew Hoffman of Toronto’s Munk School of Global Affairs. “The mandated discussions of ratcheting up countries’ commitments will be complicated if the Trump administration brashly waters down U.S. commitments. The delicate North-South bargain at the heart of the agreement might not survive the Trump administration arrogantly dismissing Paris as a bad deal while simultaneously backing off from previous climate funding pledges for the Global South.”