Here's an interesting hypothetical to ponder: What if, in the next couple of weeks, Kamala Harris picked up the phone to Joe Biden and said, "Joe, let's cut a deal. I will endorse you if you make me your running mate. If we work together we can wrap up this primary race and focus on beating Trump."

I don't think that proposition is as unlikely as some presume.

For a start, both candidates would gain much by their alliance. Biden would gain a campaigner who has the intellect and aggression to launch effective attacks on Trump and Vice President Pence. Harris would also be a formidable fundraiser with the celebrity Left. Perhaps most important to Biden, Harris would offer a female minority counterpart to his older white male identity. Being an older white male isn't exactly the favored look of the 2020 Democratic Party. Women voters are also expected to be just as critical in the 2020 elections as they were in the 2018 midterms.

What of Harris' interests?

I hear her supporters now: "Why should we accept second place on the ticket! We're here to win the presidency." Perhaps that was credible a month ago. And perhaps it will be credible again in the future. But I doubt it.

A new CNN poll on Tuesday suggests that Harris' support has collapsed. Of "Democrats/Democratic-leaning independents who are registered to vote," the poll suggests that 29% now support Biden, 15% Bernie Sanders, and 14% Elizabeth Warren. Kamala Harris is on only 5%. This should concern the Harris campaign greatly.

The senator from California was riding high following her first debate triumph over Biden. But since then, even as she has attracted more media publicity, Harris has fallen. Unsure as to her policy stance on critical issues such as health care, Harris has given Warren space to set herself as the favored liberal-alternate to Sanders. Whatever the reason, a good number of Democrats just don't seem to see Harris as their preferred president.

The question for Harris, then, is whether she continues her campaign in the hope that Warren implodes and she can pare back Biden's seemingly loyal support base. Or whether she makes the long-term strategic gambit and offers Biden the deal. Yes, the two candidates have had their frictions on the trail. But both are politicians and Harris' ambition is effervescent to anyone with eyes. At 54-years-old, four or eight years in the Naval Observatory would give Harris time to boost her profile and executive credibility in preparation for another run.

When you think about it, a Biden-Harris ticket isn't nearly as strange as you might think.