After battling his own party over trade policy for months, US President Barack Obama has won a prize no politician would envy: another fight with his friends.
Congress approved a fast-track trade negotiating authority on Wednesday after six months of cajoling by Mr Obama. It is just one step on the way to what he says will be a landmark, 12-nation free- trade agreement with Pacific Rim countries.
Democrats and liberal groups are already promising a new fight if the actual trade pact, known as the Trans-Pacific Partnership, comes to a vote. That could be early next year as the campaign to succeed him gets into full swing, putting Hillary Clinton, the Democratic frontrunner, on the spot with labour and other core constituencies.
"We all recognise that the next debate will be over Trans-Pacific Partnership itself," House Minority Leader Nancy Pelosi of California, who opposed the fast-track measure, wrote on Wednesday in a letter to fellow lawmakers. She predicted a "lively and thoughtful debate" among Democrats.
Both trade policy and relations with China - a country pointedly not part of the trade negotiations - will be topics for the 2016 races for president and Congress.
The White House wants to complete a deal this year, and Japanese Economy Minister Akira Amari said on Wednesday it might wrap up at a meeting of trade ministers in July. "The debate has only begun," said Simon Rosenberg, president of the New Democratic Network, a Democratic-leaning research group that supports Obama's trade agenda.
"The debate will shift from the abstract discussion of trade to a very specific discussion of TPP."
Trade is an issue that has divided Democrats since 1994, when the North American Free Trade Agreement, the deal labour unions blame for millions of manufacturing job losses, took effect. Clinton's husband, then-President Bill Clinton, signed Nafta and wrangled it through Congress.
With the liberal wing of Democrats gaining influence in the party and standing mostly opposed to the next, and even bigger, trade deal, Clinton has tacked left. Having once backed the accord as secretary of state, she's now wavering.
"What she made very clear from the beginning is she's going to respect the president and let him bring the deal back and she'll look at it and make up her mind," Mr Rosenberg said.
Her rival, Vermont Senator Bernie Sanders, a self-described socialist, who is Ms Clinton's main challenger for the Democratic presidential nomination, is an unequivocal opponent of the trade deal. (Bloomberg)