A reference to the Keystone XL pipeline was chopped from Hillary Clinton's memoir due to political considerations, according to the latest batch of stolen emails posted Thursday on Wikileaks.

While writing the book "Hard Choices," Clinton initially included a reference to the pipeline at the urging of her daughter, Chelsea, according to a 2014 email purportedly sent to her current campaign chair John Podesta.

"She decided to write about Keystone because her daughter suggested that it would be a glaring omission and look like an even worse dodge if she left it out," said the note from Clinton speechwriter Dan Schwerin.

The note said the passage was crafted with some help from Podesta, then edited by Bill and Hillary Clinton. The ill-fated phrases referred to Keystone XL as a tough choice amid the transition to a clean-energy economy. They concluded with Clinton refraining to take sides, out of respect for her successor John Kerry, who led the project review as Secretary of State.

Her book editor apparently wanted the section dropped — because it read like a political dodge.

Schwerin wrote: "(Editor Jonathan Karp says) it 'reads like you're punting on an issue I don't think readers are expecting you to address in the first place. Unless you feel some need to mention it, I'm not sure what the gain is. You say you're waiting for the study before making a determination, but I question whether any study is capable of defining a clear course of action, and some readers might think that relying on a study is a stalling tactic."'

It was apparently edited out at the last minute. Schwerin called it: "A change that apparently is still manageable in the production process even at this late date (let's hope it doesn't open the floodgates)."

Numerous other messages released by Wikileaks show how Clinton wrestled with the pipeline issue, which became a major Canada-U.S. irritant.

They show how her campaign team struggled with the timing, and tone, of her surprise announcement last year that she'd oppose the project — which was officially nixed shortly thereafter by President Barack Obama.

Demonstrator Sharon Garlena and others rally against the Keystone XL pipeline proposal outside the White House in Washington in January 2015. (Jose Luis Magana/Associated Press)

The latest batch of Podesta emails show how the campaign tracked the immediate media reaction to the announcement.

"Most liberals and liberal orgs are just happy that she came out with her position," campaign staffer Milia Fisher purportedly wrote to Podesta, after the September 2015 announcement.

"There are a few people... calling it a Pope-(visit)-related news dump, which is a little insane."

The Clinton campaign does not generally comment on the contents of emails published by Wikileaks, calling them an effort by Russian intelligence to sway the results of the U.S. election.

The Keystone XL pipeline would have carried more than one-fifth of Canada's oil exports to the U.S. Proponents hailed it as a cleaner, cheaper, safer way to carry oil already going to the U.S. by train — and pointed to several State Department studies that concluded it would not raise greenhouse-gas emissions.

Opponents of the project said those reviews were based on unduly optimistic assumptions about the long-term prospects for the oil industry, and some movement leaders candidly declared that their goal was simply to damage the fossil-fuel industry wherever possible.

Calgary-based pipeline-maker TransCanada Corp. has filed a $15-billion NAFTA claim against the U.S. government, arguing that while it racked up expenses, it was being misled by the Obama administration that the decision would be based on the technical merits, not politics.

The pipeline has been a minor issue in this current election, with Donald Trump and the Republicans promising to revive the project.