None of the hateful or idiotic words that have spewed forth from Donald Trump have spurred the GOP to dump their presumptive presidential nominee. Nor have Trump's policy ideas been a disqualifier — despite many of those ideas being contrary to supposed Republican orthodoxy and/or core American values.

How far must Trump go for the GOP to actually dump him? What would be their "The line must be drawn here! This far, no further!" moment? What could Trump possibly do to either prompt the party to reject him at the Republican National Convention or at least cause a tsunami of high-profile Republicans to publicly rebuke his candidacy?

Maybe there isn't anything. Maybe party loyalty and the prospect of a Hillary Clinton presidency is reason enough to support Trump, no matter what.

Or maybe not. Recall a few weeks ago when Trump told ABC News' George Stephanopoulos that taxes on the rich would "go up" once his economic proposals were negotiated with the next Congress. This immediately caused a disturbance in the force for Republicans. Big fat tax cuts, including always and forever for the rich, have been a staple of GOP economics since Ronald Reagan. Indeed, Trump's official tax plan would give the richest 1 percent of Americans an average tax cut of more than $275,000, according to the Tax Policy Center, and the richest 0.1 percent a reduction worth nearly $1.3 million.

Of course, Trump was back with a new, more Republican-friendly position the next day, telling CNN, "Now, if I increase [taxes] on the wealthy, that means they're still going to be paying less than they are paying now. I'm talking about increasing it from my [original] tax proposal." So maybe instead of cutting the top rate from 40 percent to 25 percent, he would only cut it to 28 percent or something. Still, a pretty massive tax cut for wealthy Americans.

This snafu does give you a sense, though, of a Trump break from conservative orthodoxy that might really be a bridge too far for Republicans: raising taxes on the rich.

Trump has offered more detail on taxes than perhaps any other issue, so much so that outside groups have been able to model his proposal. And the one time Trump seemed to veer off course, he quickly backtracked.

With good political reason. Trump's traditional GOP stance on taxes arguably has helped him gain and keep the support of many influential Republicans, even if they reject almost every other part of his agenda.

Consider: Grover Norquist of the influential anti-tax group Americans for Tax Reform, says a President Trump could be the most fiscally conservative president since Ronald Reagan. Now keep in mind a) the Trump tax plan would lose $1 trillion a year, b) Trump's pledge to leave entitlement spending alone, and c) how Trump apparently "love[s] playing" with debt. But Trump also wants to massively cut taxes, so apparently all is forgiven.

House Speaker Paul Ryan (R-Wis.) says he's voting for Trump. But he's had little positive to say about the billionaire businessman, particularly Trump's disavowal of Medicare reform, Ryan's signature issue. Taxes are an exception, though. Ryan has noted that the House Republican policy agenda "has been the main focus" of his "dialogue" with Trump, and that they aren't "real far apart" on tax reform.

Then there's the GOP's still influential "supply-side" wing, folks like economist Arthur Laffer, policy journalist Stephen Moore, and CNBC commentator Larry Kudlow. Their love of Trump's tax plan seemingly has allowed them to embrace the candidate — if not officially endorse him — despite his anti-trade stance. This is a telling concession since supply-siders view protectionism as a cardinal sin, blaming it for the Great Depression.

Trump's vow to cut taxes on the rich has helped bring him the support of key Republican constituencies. If he abandoned this position, would the GOP abandon Trump? After all, it was once said about the GOP, "God put Republicans on Earth to cut taxes."

Maybe. Possibly. Because in today's GOP, tax cuts seem to trump all. Which is sad!

First, high-end tax cuts should not be an economic priority in 2016 compared to, say, education or regulatory reform. Second, tax cuts more generally don't have the political oomph they used to. Third, the mercurial Trump may not even follow through with his tax plan if elected. He calls it "a concept," muses how the rich would be willing to pay higher taxes, and used to support a massive wealth tax. Perhaps the only issue on which he's been long-term consistent is opposing free trade.

Finally, to brush aside Trump's racial and religious divisiveness and his disinterest in basic civil liberties because he supports a particular tax policy position or any other policy issue reveals a deep moral confusion inside the Party of Lincoln.

Sad, indeed.