WASHINGTON (AFP) -- A U.S. newspaper has published a mockup of what a frontpage might look like should Republican frontrunner Donald
 Trump win the presidency, as it condemned his "deeply disturbing" and "profoundly un-American" vision.

"Deportations to begin, President Trump calls for tripling of ICE (immigration and customs enforcement); riots continue," read The Boston Globe's fake headline, dated April 10, 2017.

It was posted on the editorial page, accompanied by a ruthless editorial article saying Trump's campaign "demands an active and engaged opposition."

The mockup was published just three months before the Republican National Convention confirms the party's nominee, with speculation growing over what Trump might do should he actually win the highest office in the land.

On the page are several articles, including one on U.S. soldiers refusing to follow orders to kill the families of members of the so-called Islamic State group, another on a Republican-controlled Congress passing a libel law targeting "absolute scum" in the press.

A separate article details how Trump sparked a diplomatic crisis with China after naming his dog, a Shar-Pei, after Chinese First Lady Peng Liyuan.

"I don't know why she's so offended, I love cute puppies and I love women! It's not like I tweeted out a photo of a Rottweiler named (German Chancellor Angela) Merkel," he was quoted as saying.

A note from the editor at the bottom of the page warns readers that "what you read on this page is what might happen if the GOP frontrunner can put his ideas into practice, his words into action.

The accompanying editorial urges Republicans to oppose Trump.

"Donald J Trump's vision for the future of our nation is as deeply disturbing as it is profoundly un-American," it said, warning that Trump could be one of the world's next "demagogic strongmen."

The satirical frontpage "is an exercise in taking a man at his word. And his vision of America promises to be as appalling in real life as it is in black and white on the page," the editorial said.

"It requires an opposition as focused on denying Trump the White House as the candidate is flippant and reckless about securing it."

It pointed to Trump's "winks and nods at political violence at his rallies," among other controversies.

"If Trump were a politician running such a campaign in a foreign country right now, the U.S. State Department would probably be condemning him," it added.

"For now, Republicans ought to focus on doing the right thing: putting up every legitimate roadblock to Trump that they can."

Urging Republican leaders to pick an alternative nominee, such as House Speaker Paul Ryan or businessman and former Massachusetts governor Mitt Romney, the Globe's editors noted: "It is better to lose with principle than to accept a dangerous deal from a demagogue."