Donald Trump couldn't make the argument at all cogently when he had the chance in Monday's debate, so let's be nice to the poor man and do it for him.

Let's assume -- purely for the sake of argument -- that the Trump campaign is correct when it clearly is not. Let's say that in some small way, the nonsense involving Barack Obama's place of birth did indeed have its origins in the depths of the Clinton campaign against Barack Obama in 2008, and that even the firing of a Clinton volunteer who might have briefly spread the notion was not enough to absolve the campaign of responsibility for that ugliness.

Clearly, the Trump campaign would have us believe that the Clinton '08 campaign did a bad thing, something blameworthy, something of which it should be ashamed, something for which it should be held accountable in the court of public opinion some eight years later. Again, for the sake of argument, let's assume the Trump folks are right about that too.

So, accepting the truth as the Trump campaign would have us believe it, let's weigh these relative sins on the scales of justice:

Hillary Clinton did not claim to send investigators to Hawaii to ferret out the truth, promising that those detectives had already found amazing things. She didn't spread repeated rumors on national TV about Obama's true place of birth, or demand to see his college transcripts, or claim that Obama's grandmother had witnessed his birth in Kenya. She didn't claim that "there’s something on that birth certificate he doesn’t like.” She didn't do any of that, and neither did anyone in her campaign.

Trump did all that and more.

Trump now claims credit for somehow forcing Obama to release his official birth certificate in 2011, thus putting an end to the controversy. But in 2012, Trump went on CNN to suggest that the birth certificate was a forgery.  He also tweeted regularly in 2012 in support of various birther conspiracy theories. For example:

"Why does Barack Obama's ring have an Arabic inscription? Who is this guy?" (Note: Obama's wedding ring has no such inscription).

"What a coincidence--Michelle Obama called Kenya @BarackObama's "homeland" in 2008!"

Here's Trump in October 2012, more than a year after he had allegedly "settled" the birther question and moved on:

In 2013, after Obama's re-election and more than two years after the birth certificate release, Trump was still at it.

And on and on it went, well into 2015 at least. To this day, according to the polls, some 70 percent of Republican voters are still unwilling to acknowledge that Obama is fully qualified under the Constitution to be our president. Trump bears a substantial degree of responsibility for that.

So again, let's give Trump the benefit of every non-existent doubt and accept the set of "facts" that he puts forward: If the Clinton campaign from back in '08 deserves some degree of blame for the rise of birtherism -- and again, it does not -- then the degree of blame that must fall on Trump for his systematic, sustained public crusade in support of this pernicious "controversy" must be enormous, correct?

And no, don't give me this lame excuse about "this isn't important, let's move on to important things." For five years or more, as long as he could milk attention and celebrity from it, Trump thought it was very, very important. Look at the billing for the video above: "From the desk of Donald J. Trump: A major announcement". It was so important that Trump was allegedly willing to give away $5 million -- remarkable given what we've learned since about his attitude toward charity -- in order to again "put the matter to rest".

Trump built the early stages of his presidential run on the foundation of birtherism.  He took apparent joy in encouraging his fellow Americans to believe that our first black president was an illegitimate president, someone with no legal claim on the office, someone perhaps planted here by Muslim agents out to undermine the nation from within. He was willing and even eager to truck in the most nonsensical conspiracy theories, even if it meant undermining the fundamental credibility of our government and impugning a truly historic event for black America, for all of America.

So yes, that is absolutely a factor that ought to be weighed heavily when considering his qualifications for high office.