Some members of the GOP have been making a more concerted effort to draft an independent candidate to block Donald Trump, the likely Republican presidential nominee, in this season's bid for the White House. Mark Cuban says he was approached for the job.

The billionaire entrepreneur and Dallas Mavericks owner said that these Republicans pride his "bluster and volume, combined with substance and the ability to connect with voters on a more personal basis," in an email to The Washington Post.

Still, a Cuban presidential bid is off the table, as he rejected the possibility almost immediately. "He [Trump] could come at me all he wanted, and he knows I would put him in his place," he continued. "All that said, again, I don't see it happening. There isn't enough time."

Other conservatives approached to run as a third-party candidate, according to the Post, have included Sen. Ben Sasse (R-Nev.) and Ohio governor John Kasich, who recently ended his Republican presidential bid. Earlier hopefuls included former secretary of state Condoleezza Rice, and retired army general Stanley A. McChrystal.

Cuban has a point: Republicans spearheading the push for a third-party candidate, led by 2012 presidential nominee Mitt Romney -- as part of the so-called "Never Trump" movement -- are running out of time to clinch the ballot. The deadline to register an independent candidate in Texas, the state with the second-largest share of electoral votes, has already passed, and other states' deadlines are approaching quickly. Generally speaking, independents need to collect more than 880,000 signatures, including nearly 180,000 in California alone, to get on the ballot, according to Ballotpedia.

It's worth pointing out that third-party promoters do not necessarily represent the views of a GOP majority. "You're talking about a very shallow group," Ed Cos, a Trump supporter and chairman of the New York Republican Party, told the Post, insisting that such promoters are more concerned with "their own intellectual constructs" than with what the people want.

Many also argue that registering a third-party candidate would effectively guarantee a Democratic president, by creating a bigger rift in the Republican Party. In a recent interview with Reuters, Republican National Committee chairman Reince Priebus equated an independent bid to the  death of the GOP in this election season: "They may as well jump off the top floor of a building because that's what we'd be doing by having a third party," he said.

Even so, such conservatives are bullish, insisting that a three-way election could attract more global attention -- and could therefore be a great platform for the candidate to promote his or her ideas. So far, though, Cuban isn't alone in rejecting the offer: Kasich's advisors have reportedly dismissed the notion, while Sasse has publicly done the same.

Cuban, for his part, has waffled on his views on Donald Trump over the past year. Although he claimed that he'd consider running as vice president on a Trump-led ticket just months ago, he recently called Trump an "airhead," and indicated that Hillary Clinton should choose someone like him -- who would "throw bombs at Donald [Trump]" -- as a running mate, speaking at the economic summit SkyBridge Alternatives Conference last week, CNN reported.

More colorfully, he went on to liken the Republican front-runner to "the guy who'll walk into the bar and say anything to get laid."