(Newsmax) – This Memorial Day weekend may mark a turning point in what one pundit called the “weirdest” election ever as news that a third party candidacy became real.

Bill Kristol, one of the nation’s leading conservatives and editor of the influential Weekly Standard, tweeted on Saturday: “Just a heads up over this holiday weekend: There will be an independent candidate – an impressive one, with a strong team and a real chance.”

This triggered a barrage of tweets from GOP presumptive nominee Donald Trump, who dissed Kristol as a “dummy” and an “embarrassed loser.”

But if the news is true, it could be bad news for Trump, who himself had threatened a third party bid during the early stages of the GOP primary.

SPECIAL: Send every Congressional legislator a STOP THE ESTABLISHMENT LETTER and demand they resist the Washington Elite’s plan to destroy America!

On Monday, NBC News listed potential independent candidates Kristol may have in mind.

The network identified Mitt Romney, but said sources close to the former Massachusetts governor saw his entrance into the race as “unlikely.”

They also discounted Nebraska Sen. Ben Sasse, a strong critic of Trump, signing on.

But the network identified potential wildcard choices, including former Secretary of State Condoleezza Rice and current New Mexico Gov. Susana Martinez.

But the Kristol news indicates Trump appears to have failed in winning over key conservative base support as he prepares for the RNC’s July convention in Cleveland, usually a unifying event for the party.

Two leading conservative thought publications – Kristol’s Weekly Standard and National Review, remain staunchly opposed to his candidacy, even with Trump close to holding the official Republican imprimatur.

Trump has won over a number of establishment endorsements, but still, many have remained on the sidelines, including current House Speaker Paul Ryan.

On Sunday, the Washington Post headlined, ”Even in victory, Donald Trump can’t stop airing his grievances.” The accompanying article detailed Trump’s attacks last week on a slew of personalities that may be giving pause to GOP party leaders.

Trump’s targets included the Hispanic judge overseeing the civil suit he faces over Trump University, Gov. Martinez, and Mitt Romney, among others. Trump said Romney “walks like a penguin.”

Romney, like Kristol, has been a leader in efforts to recruit a third-party candidate who could not only stop Trump, but perhaps win a three-way race.

Backers of the third party bid think that both Trump and presumptive Democratic nominee Hillary Clinton have extremely high negatives among voters.

This, coupled with the fact that Trump may cut into union, blue collar and some ethnic voters that traditionally vote Democratic, may open the door for a conservative third party candidate becoming viable – and even winning in once die-hard Blue States.

Trump’s campaign manager Paul Manafort told ABC’s “This Week” on Sunday that Romney’s efforts to stop Trump were motivated by “jealousy.”

In a Saturday Wall Street Journal story, Romney explained his own reason for taking on Trump.

“I wanted my grandkids to see that I simply couldn’t ignore what Mr. Trump was saying and doing, which revealed a character and temperament unfit for the leader of the free world,” Romney said.

He added: “Friends warned me, ‘Don’t speak out, stay out of the fray,’ because criticizing Mr. Trump will only help him by giving him someone else to attack,” Romney said.  ”They were right. I became his next target, and the incoming attacks have been constant and brutal.”

A recent Washinton Post-ABC News poll found that in a three-way race, Romney would draw 22 percent of the vote against both Clinton and Trump. This makes him not only a strong contender, but he could qualify for presidential debates, which require a 15 percent threshold in national polls.

The Journal quoted a Romney confidant as saying his friend is determined: “He feels like the last lion.”

Trump adviser Ben Carson suggested an independent bid would hand the White House to Hillary.

And Trump, in his twitter storm against Kristol, wrote that if he “actually does get a spoiler to run as an Independent, say good bye to the Supreme Court!”

But Kristol and anti-Trump conservatives like Erick Erickson, founder of Red State, believe Trump will lose decisively to Hillary Clinton come November. The loss will not only dash GOP hopes of winning the White House, but end Republican control of the Senate as the party faces more than a half dozen toss-up races across the country.

“If that happens, the Republicans can kiss more than the Supreme Court good-bye, but perhaps the whole federal judiciary,” a Republican congressman who opposes Trump told Newsmax.

NBC, citing sources, said the Trump challenger may come forward as early as this week.