Most people don’t really believe the blustering billionaire buffoon currently at the top of the GOP charts will win the Republican presidential nomination, much less the presidency.

I think they might be underestimating the Obama-era right’s susceptibility to high-volume fear-fueled ugliness, and its insatiable appetite for dripping red meat.

Far more likely, we’re underestimating the politically inept left’s perpetual insistence on all or nothing, which invariably produces the latter.

Certainly we know Donald Trump can deliver the ugliness, the noise and the meat. His supply of those things is apparently as inexhaustible as his wealth, his only areas of bankruptcy being scruple, taste and fact.

A favorite editor years ago shared some valuable advice: “If all you do is scream,” he said, “nobody will ever hear you whisper.”

Most of what we’re getting now is screaming. This is most evident in Republican responses to pretty much everything Barack Obama does or says. His every action or utterance is the worst ever, the most tyrannical, most outrageous, most egregious, most unconstitutional, most overreaching, most despotic, most socialistic, most Stalinesque, most Hitlerian, etc.

The problem with that kind of relentless and unmodulated noise is that when you have a reasonable beef — and Obama has provided legitimate reasons for more than a few — only the already-converted are still listening.

Trump is making himself heard above that noise by moving on from Obama and insulting everybody else in both parties. There are, for whatever unfathomable and sub-rational reasons, people who consider that leadership.

Republican primary voters should take care of the Trump problem themselves, but we come to the real danger if they don’t. Call it the “Nader effect.”

Hillary Clinton, barring some catastrophe or total political meltdown, is going to be the Democratic nominee. She has credibility and likability issues.

Then there’s Bernie Sanders. A lot of the people who like Sanders are genuinely passionate.

But Sanders is a self-defined socialist, which makes him unelectable. Period. As the year and the primaries go on and Clinton’s nomination becomes a certainty, Sanders should step aside.

If instead — and this is what will keep me awake nights — Sanders decides to mount an independent challenge, he could split the far left off from more moderate liberals and what’s left of the old Clinton conservatives, and guarantee a Republican presidential victory. If Trump is the GOP nominee in that scenario, it will be the left that will have put him in the White House.

This is the kind of thing liberals do — like the folks in 2000 who decided Al Gore wasn’t liberal enough.

Granted, this isn’t just a habit of the left-leaning. There will be votes for the Libertarian candidate and the Green candidate and the Patriot Party candidate and countless other “statement” votes for unelectables. “I have the right to vote for anybody I want to” is the unarguable and, in real world politics, utterly irrelevant reasoning of these citizens.

The political savvy, common sense and, I hope, common decency of Republican voters is a better bet to keep Trump out of the White House than the quixotic cluelessness of Democrats.

Either way, somebody needs to make a serious defensive stand here.

Dusty Nix is the editorial page editor at the Columbus Ledger-Enquirer (Columbus, Ga.).