Given the polls, it is perhaps time to try to conceive the inconceivable. And let's start with this:

If Donald Trump manages to win the election, he would have a mandate. That mandate would not be specific or limited in nature; it would be expansive. Trump could legitimately claim authority from the voters to do just about anything that he damn well wants to do.

Now, that's not what apologists and sophists in Washington would have you believe. To reassure nervous voters, his fellow Republicans talk soberly of the checks and balances that were carefully written into the Constitution, about the constraints imposed by the separation of powers. Yet the necessity of even saying such things tells you that something different is afoot -- members of Congress don't typically go around promising constraints on a potential president of their own party.

“What protects us in this country against big mistakes being made is the structure, the Constitution, the institutions,” as Senate Majority Leader Mitch McConnell put it. “No matter how unusual a personality may be who gets elected to office, there are constraints in this country. You don’t get to do anything you want to.”

House Speaker Paul Ryan takes a similar tact, continuing to act as if the House, not a President Trump, would take the lead in setting policy through its "A Better Way" agenda, even though that agenda contradicts Trump in important ways. In addition, Ryan promises, “I would sue any president that exceeds his or her powers.”

But if we look at it honestly, such talk isn't plausible. Ryan and McConnell do not seem to comprehend that Trump's campaign is a revolt against the very idea of checks and balances. His voters are frustrated that Washington hasn't been able to give them what they want, and if he wins in November, neither he nor they are going to be in a mood to be told no. What they want, they will demand, and what they demand they will get, at least initially.

It's a painful exercise for some of us, but try to imagine the triumphalism of the right-wing entertainment/media complex in the wake of a Trump victory --- imagine the passion and expectations driven by the talk shows and the web sites and Fox News. Imagine how ignited the GOP base would be by a Trump victory and the defeat of the hated Clintons. It would be the Tea Party at its 2010 peak multiplied a hundred times, a thousand times, and Trump would be its conquering hero.

It's also important to note that Trump has never been a respecter of the rules in any part of his life. In business as in his personal relationships, he has always pushed things as far as they can go in his favor, and then has pushed them farther still until he meets resistance that he cannot overcome. And it's hard to imagine where that resistance would come from.

In that post-election euphoria, the likes of McConnell and Ryan would no longer be leaders of the Republican Party, secure in their own base of power; they would be reduced to functionaries in Trump's movement. If Ryan tried to block a major Trump initiative in the House, for example -- if he dared to propose a lawsuit against a Trump overstep -- he would be howled out of the speaker's job and replaced by someone more obedient. That is not conjecture, that is fact.

Remember, the Republican establishment wasn't able to stand up to Trump when he was merely one of 17 candidates for the nomination; they haven't been able to stand up to him now that he's their party's standard bearer. They certainly won't be capable of standing up to him should he win the presidency.  In fact, their reassurances to the contrary come off as quaint and naive, the bleating of stupid sheep about to be shorn of their delusions.

Look at what's happened to Reince Priebus. The once-independent head of the Republican National Committee is now issuing dictates on Trump's behalf, warning that former GOP presidential candidates -- Ted Cruz, John Kasich, Jeb Bush -- had better fall in line behind Trump or be denied the right to run for president in the future.

"Those people need to get on board," Priebus said over the weekend. "And if they’re thinking they’re going to run again someday, I think that we’re going to evaluate the process – of the nomination process and I don’t think it’s going to be that easy for them."

The dangers are particularly apparent on issues of diplomacy and military policy, where there are few reins to be pulled in the first place. The Constitution already gives the executive branch enormous leeway in such fields, and what little control the Founders did provide to the legislative branch has atrophied over decades of congressional acquiescence to presidential initiative.

In addition, in a Trump administration we're unlikely to see experienced, moderating voices at the State Department, at the Pentagon, in the National Security Council. The traditional Republican foreign policy and national security establishment has already made it quite clear that it wants nothing to do with their party's nominee, and in fact is supporting Clinton.

As more than 120 GOP foreign-policy experts put it in an extraordinary letter released back in March:

"Mr. Trump’s own statements lead us to conclude that as president, he would use the authority of his office to act in ways that make America less safe, and which would diminish our standing in the world. Furthermore, his expansive view of how presidential power should be wielded against his detractors poses a distinct threat to civil liberty in the United States. Therefore, as committed and loyal Republicans, we are unable to support a party ticket with Mr. Trump at its head. We commit ourselves to working energetically to prevent the election of someone so utterly unfitted to the office."

True to his nature, Trump has returned their disdain many times over.  He has made it quite clear, repeatedly, that he won't be turning to "the Washington elite" to fill top national-security and foreign-policy positions, and will instead turn to figures who have long been considered fringe players in those fields. For example, as secretary of Defense he has already proposed former Lt. Gen. Michael Flynn, whom Colin Powell described in leaked emails as “a jerk” -- "unchained” and "right-wing nutty."

These are not people likely to challenge Trump.

During a debate on Fox News back in the primaries, Trump was asked what he would do if the military refused to carry out what it considered to be an illegal presidential order, such as implementing torture or killing the families of terrorists:

“They won’t refuse. They’re not gonna refuse me. Believe me,” Trump said. “I’m a leader, I’ve always been a leader. I’ve never had any problem leading people. If I say do it, they’re going to do it.”

Again, for many if not most Trump voters, this is not a problem. That attitude is precisely why they are voting for him, and it is precisely how they will demand that he act if elected. I'm not sure that the structures and constraints cited by McConnell are capable of standing up to that if the voters make it clear in November that they no longer support such niceties.