As Bernie Sanders's odds of winning the Democratic Party nomination have shrunk toward nothingness, talk has naturally turned to party unity. Sanders is promising to do everything in his power to keep Republicans out of the White House, but also suggesting that concessions may be needed from the Clinton camp to spur enthusiasm on the part of his voters.

The reality, however, is that nobody is better positioned to make the case to Sanders voters than Sanders himself. And Sanders already has all the reasons he could possibly need to give Clinton his full-throated support.

Thanks to the primaries, Sanders has emerged as a substantial factional leader inside the Democratic Party — someone whose statements and tweets will garner media attention, whose email list will be coveted and envied by other Democrats in Congress, and whose support or opposition to a measure will matter to a national constituency. That gives him, potentially, considerably more influence over national affairs than he's had in his previous 25 years in Washington. But essentially all of that influence hinges on Clinton winning the election in November.

That, rather than anything to do with platform concessions or "lesser of two evils" talk, is why Sanders will almost certainly do everything in his power to boost Clinton this fall. He'll do it because it's the right thing for Bernie Sanders.

A Hillary win advances Bernie's issues

Clinton and Sanders have profoundly different political styles and have adopted meaningfully distinct stances on the issues in 2016. But unlike the differences between Donald Trump and the Republican Party leadership he displaced, Clinton and Sanders are pulling in the same direction on almost every issue.

Sanders wants to raise the federal minimum wage from $7.25 an hour to $15 an hour; Clinton wants $12.

Sanders wants a massive increase in taxes on the wealthy; Clinton wants a modest one.

Sanders wants a big new government-run health insurance program to cover everyone; Clinton wants to expand an existing government-run insurance program to cover more people.

Sanders wants a hard cap on bank size and complexity; Clinton wants enhanced capital requirements for large and complex banks that would discourage size and complexity.

This is how it goes across the board. On virtually every issue, Sanders has promised to go further than Clinton has in the same direction. Which is another way of saying that implementing Clinton's agenda would be a way of moving closer to Sanders's goals — so in pursuit of his goals, he's going to want to put her in the White House.

Video: Bernie Sanders explains his political revolution

A Hillary win gives Bernie leverage over appointments

As we've seen several times during the Obama administration, left-wing Democratic Party senators have a decent chance to block executive branch appointees they don't like. That's why Janet Yellen rather than Larry Summers chairs the Federal Reserve, and it's why Antonio Weiss's nomination to be undersecretary in the Treasury Department got spiked.

Not just any senator can blow up any appointment, but a senator like Sanders with a constituency and a loyal following has a good chance of doing it.

But this only works if Clinton is in the White House. Senators have a lot of leverage of their own party's presidential nominees, because in a polarized era it generally takes near unanimity to get things done in the Senate. But by the same token, nobody is going to care about a left-wing Democrat opposing a Trump administration appointee.

It's not just a question of whether Sanders would likely prefer Clinton's appointees to Trump's (though he would) — he'll have a concrete ability to influence how she builds her team that won't exist with a Republican in the White House.

A great year for Democrats makes Bernie a committee chair

Last but by no means least, if Democrats can exploit Trump's weakness as a candidate, they are in good position to secure a majority in the United States Senate.

Sanders is a relatively senior Democrat, and in that scenario should be in a position to become the chair of the Health, Education, Labor, and Pensions Committee. (He's currently the top Democrat on the Budget Committee — which isn't as important as it sounds, but Patty Murray will likely take over Appropriations with the retirement of Barbara Mikulski, which clears the doors for HELP.) As chair, he'll have influence over legislation, of course, but also the ability to call hearings on whatever subject he likes.

If Sanders can't be president, he'd surely enjoy the opportunity to offer a platform to proponents of expanding Social Security and terrorizing the health care industry.

Obviously in principle Democrats could take the Senate without Clinton winning the presidential election. In practice, however, things are more closely tied together than that. For Sanders to maximize his personal political clout in 2017, he needs to do what he can to get liberals who feel the Bern fired up about voting in November.

This is why Donald Trump can't win a general election