The VP job has become increasingly important. But Pence and Kaine shouldn't get their hopes too high.

Tales of powerless, miserable, humiliated vice presidents of the United States are legion. John Adams, the office’s first occupant, once proclaimed the job is "the most insignificant office that ever the invention of man contrived or his imagination conceived." FDR’s first vice president, John Nance Garner, later said the job was "the worst thing that ever happened to me." And even Lyndon B. Johnson, who many pundits believe had wizard-like political powers, couldn't make anything of the office, and once said that "being vice president is like being a cut dog."

So you could be forgiven for not being too excited about Tuesday’s Mike Pence/Tim Kaine VP debate.

But I’m here to tell you that you should be. Well, at least a little bit. Maybe.

Now, the office of the vice presidency has always had immense potential importance. Fourteen of our 47 veeps have in fact gone on to become president — eight through the sitting president’s untimely death, one through scandal followed by resignation, and five through later being elected on their own. And it’s worth noting that this year, both presidential nominees are relatively old and have been plagued by various scandals, so the odds are not all that bad that Kaine or Pence could wind up in the Oval Office.

But in addition to all this, the job of the vice presidency has also become increasingly important in its own right in recent decades. Basically, the role of the veep has evolved into that of a top adviser to and surrogate for the president, both in the administration and on the Hill.

The only problem for Pence and Kaine is that there are serious reasons to doubt whether this trend will continue under their respective running mates.

The Constitution gives the vice president the duty of certifying the next election’s Electoral College results (which is almost always a formality) and the power to cast tie-breaking votes in the Senate (which is rarely necessary).

And that’s basically it as far as formal powers go — which is why so many of the office’s occupants have been so miserable. Essentially, the vice president only gets to do anything important if the president wants him to.

Yet starting with Walter Mondale and continuing with Al Gore, Dick Cheney, and Joe Biden, the role of the vice president has gradually evolved into "an across-the-board presidential adviser and troubleshooter to help presidents identify and achieve administration goals," as Joel Goldstein put it. Mondale himself made the case to his boss, President Carter, that he could use a general adviser of this type, and future presidents have found the function useful to them too.

Cheney in particular exerted immense influence with these roles in George W. Bush’s administration, particularly during his first term, as Barton Gellman and Peter Baker have chronicled at book length. Bush was a president who lacked experience in many major issues, and on many important topics — particularly those related to national security after 9/11 — he sided with Cheney’s advice at first.

Joe Biden has much less of a "puppet master" reputation compared with Cheney, but as the Atlantic’s Michael Hirsh has written, he’s been omnipresent in major administration debates and policy initiatives, and played an important role representing the White House in negotiations with congressional Republicans.

Hirsh argues that Biden could be "the most influential vice president in history," which seems overstated to me — after all, his skepticism about escalating the war in Afghanistan and intervening in Libya was ignored, as Isaac Chotiner points out. But certainly Biden has been an important figure in the administration, similarly to the way Cheney was important in the Bush administration — as, essentially, a high-powered staffer.

The caveat to all this good news for the vice presidency is that the next president gets to decide whether these trends will continue. After all, Vice President Cheney’s influence over President Bush declined precipitously in their administration’s second term simply because Bush became disenchanted with him and sought counsel elsewhere.

And there are good reasons to doubt whether Clinton or Trump will want such an empowered veep.

On the Democratic side, the big questions are whether Clinton really needs another trusted counselor, and whether Kaine can carve out a place for himself in the tangled thickets of Clintonworld and Hillaryland.

Clinton already has an extensive network of political hands and advisers built up over decades from her husband’s presidency, her years in the Senate, her 2008 campaign, her secretary of state tenure, and her current campaign, not to mention Clintonista-heavy outlets like the Center for American Progress. She even already has a Virginia governor she trusts more than Tim Kaine on her speed dial in longtime ally and friend Terry McAuliffe.

So it seems that Clinton really won’t need very much from Kaine. It is possible that she may bond with him and come to trust him and therefore choose to delegate him significant authority. Alternatively, she could throw him a few scraps to keep him from complaining too much, while keeping the real power with herself and her top aides.

The situation on the Republican side seems even more up in the air, since no one really has any idea how Donald Trump will govern. The New York Times’s Robert Draper did report earlier this year that one of Trump’s sons was going around saying that Trump would give immense powers to his veep, putting him in charge of domestic and foreign policy (which is, well, basically pretty much everything), while Trump would be in charge of "making America great again." Perhaps Trump will indeed have little interest in the nitty-gritty of governance and delegate essentially everything to his veep.

But that seems to me to be very unlikely to work out so simply. The problem with the vice presidency is that unless Trump makes it crystal clear that Mike Pence and only Mike Pence is in charge of policy, Pence will be pretty powerless to get his way on anything, because he, as mentioned, will have hardly any formal powers. And what about Trump’s chief of staff, his top political advisers, his Cabinet secretaries, his family members — and of course, Trump himself?

Furthermore, the constantly warring factions of the Trump campaign don’t particularly instill confidence in Trump’s ability to delegate so much to one individual. And Pence himself has exerted little apparent influence over the Trump campaign so far, with the candidate apparently continuing to heed his own counsel and that of his hand-picked advisers. Indeed, Pence often seems to be running an entirely separate campaign from Trump. This does not suggest the closeness with the running mate that is typical of most successful vice presidents, let alone a vice president who will supposedly be handed immense power over pretty much all policy.

It’s also worth noting that one of the main reasons Cheney and Biden could exert such influence is that both were elder statesman figures who weren’t viewed as having serious ambitions for the presidency themselves. (Biden did flirt with a bid last year, but Obama never seems to have taken it seriously.) Therefore, their advice could be trusted as what was best for the president, not what was best for their own political futures. That hasn’t been the case for past vice presidents who were viewed as potential successors whose interests could conflict with those of the incumbent.

Kaine and Pence are in the mold of the younger veep with their own political futures ahead. So unless they become very good soldiers indeed (like Vice President George H.W. Bush did for President Ronald Reagan), they risk being viewed as ambitious upstarts — and being put on ice. Because the vice presidency is only what the president chooses to make of it.