Why I think Bernie Sanders has stayed in the race so long

Bernie Sanders doesn't have a realistic path to the Democratic nomination, even with superdelegates excluded, and hasn't had one for more than two months now.

Yet the Vermont senator has remained in the race, and has repeatedly suggested he'll fight it out "until the last vote is cast." Indeed, on Tuesday night he said he still intended to win "a majority of pledged delegates," even though he has to win the remaining contests by enormous margins to pull that off.

This persistence may seem surprising, particularly when compared with the Republican contest, in which everyone has already stood aside for Donald Trump. And some have even suggested Sanders is not being entirely on the level with his supporters about how he views his chances.

Meanwhile, others point to a top Sanders aide's suggestion a few weeks back that Sanders would keep campaigning all the way to the Democratic convention in July (focusing then on getting superdelegates to swing to his side), and suggest that Sanders himself is either "delusional" or intent on burning the party to the ground. His handling of a recent controversy involving Nevada delegates has inflamed those fears.

I have a different view, and it's rooted in Sanders's career history, which I've written about at length. There are two sides to Bernie Sanders that can seem somewhat contradictory — the long-shot electoral gadfly and the canny pragmatist focused on results.

The key to reconciling them in this situation, I believe, is noting that Sanders has not been mathematically eliminated yet — not from winning an outright delegate majority or a majority of pledged delegates.

Bernie Sanders has ample reason to scorn political experts' conventional wisdom

To win that pledged delegate majority, Sanders needs 67 percent of all the remaining pledged delegates (more than half of which are in California alone). Most electoral analysts say that's not going to happen, and I happen to agree with them.

But if Sanders had listened to electoral analysts and experts about what is and is not possible, he wouldn't even have his political career.

For decades, he's run in elections that the political cognoscenti has given him no chance of winning — and managed to shock them by winning a fair amount of them.

• In 1981, hardly anyone expected that a three-time losing third-party candidate and self-identified "socialist" could dethrone the Democratic establishment to become mayor of Burlington, Vermont.
• Everyone certainly thought the "democratic socialist" label was political poison for a career in national politics, but Sanders built one anyway.
• Most electoral analysts thought an independent couldn't get elected to Congress, because no one had managed to do it for 40 years — until Sanders shockingly pulled it off in 1990.
• And, obviously, most electoral analysts never expected Sanders to get this far in his presidential run, instead assuming it would be a cakewalk for Hillary Clinton. (Plus, that whole Donald Trump thing sure disproved the experts.)

There have also, of course, been many times that the experts were right and Sanders was wrong. But overall, Sanders has ample reason to disregard their conventional wisdom about the electoral prospects of Bernie Sanders.

But Bernie Sanders is not delusional

Still, the other side of Sanders is that he can be a surprisingly pragmatic operator, as demonstrated through much of his political career.

• Once mayor of Burlington, he eventually developed a pretty good relationship with local business interests.
• When he got to the House, despite holding on to his "independent" title, he quickly decided that caucusing with the Democrats was the only way to get anything done.
• He was once dubbed the House of Representatives' "amendment king" for his surprising ability to get his amendments approved on the floor.
• He harshly criticized President Obama's health reform bill and refused to commit to supporting it — but quickly got on board when he won a big concession.

And most importantly and relevantly of all, Sanders has been crystal clear for years — including in this campaign — about the fact that he considers the Republican Party far, far worse than the Democratic Party, and that he believes it's incredibly important to keep the White House out of Republican hands. "On our worst days," he said during a February debate, "we are 100 times better than any Republican candidate."

Furthermore, if Sanders truly wanted to burn the Democratic Party to the ground, he'd be in the press attacking the likely Democratic nominee on her email scandal every day. But he's not.

I have no inside knowledge about what Sanders or his top aides are thinking right now. But judging from what I know of his career and background, and how he's acted so far in this race, I find it hard to imagine that he will keep contesting the nomination all the way to the convention (or try to supplant the pledged delegate winner by lobbying superdelegates).

It seems more likely to me that if and when Hillary Clinton clinches a majority of pledged delegates — likely on June 7 — Sanders will reevaluate. He may hold out for a bit. He may play hardball. He may fight for concessions of some kind. But my guess is that he'll end up endorsing her and focusing on the effort to stop Trump.

Watch: Where our modern primaries came from