Bernie Sanders may have lost the current battle for the Democratic nomination. But he's winning the war for the party's future.

That, at least, is the conventional wisdom about Sanders's campaign — that while the Vermont senator may go down to defeat in this presidential cycle, his young supporters can expect sweeping victory within a generation or two.

"Whatever Sanders’s fate as a presidential candidate ... his campaign is the harbinger of a deep change in the Democratic Party," wrote the New Republic's Jeet Heer after Sanders won New Hampshire. "In coming years, Democratic politicians will have to echo Sanders’s slashing critique of Wall Street and his call for a far more robust welfare state if they want to hold on to the rising generation in their party."

But Dave Hopkins, a political scientist at Boston College, thinks these kinds of interpretations may be overstating the long-term significance of Sanders's insurgency.

"There's a temptation to assume that everything new in politics is a harbinger of the future. But lots of things are dead ends: They rise, and they go away," Hopkins says. "There's no reason to believe just definitionally that Sanders represents the future of the Democratic Party more than anybody else."

For one, Hopkins sees little reason to believe that the young voters who have overwhelmingly backed Sanders will remain wedded to his political vision. And the title of most popular Democrat still belongs to the man in the White House: Barack Obama continues to command massive popularity among the Democratic rank and file — about 80 percent of Democrats approve of his job performance.

"It seems like [Obama] will go down in history as the key figure in current Democratic Party politics — he showed how the party's new demographic coalition could come together. If you want to talk about the future of the Democratic Party, that's where it is," Hopkins said.

In a phone call earlier this week, Hopkins told me why he thinks Sanders has failed to transform the Democratic Party this time around, and why — media speculation aside — he probably doesn't represent its future either.

A transcript of our conversation, lightly edited for length and clarity, follows below.

Has Bernie Sanders pulled the party to the left?

Jeff Stein: I want to get a sense of the extent to which you think Sanders has pulled the Democratic primary to the left. On some of these issues — the Trans-Pacific Partnership, wealth inequality, the minimum wage — hasn't his message changed Clinton's?

Dave Hopkins: I think Sanders has had a visible effect on the rhetoric of the Clinton campaign, where they clearly took seriously the critique that she was not really liberal enough and responded to Sanders's presence in the race.

"I'm not sure whether we'll see a substantive lasting effect of the Sanders campaign"

TPP is the one example where there may have actually been a substantive position change in response to him. The rest haven't been substantive position changes but rhetorical and message differences — and, maybe, emphasizing Wall Street regulation, the public option on health care, and more debt free college.

But she didn't adopt all of his positions, or even many of them. At most, she may have "me, too'd" some issues more than she would have otherwise.

JS: Okay, maybe Sanders didn't force many substantive concessions. But didn't he at least move the party to talk more about inequality? Clearly the primary at least showed future Democratic politicians the potency of his attacks on the 1 percent and the "millionaires and billionaires," right?

DH: I think it was already there to a large extent. It's an issue that Democrats more generally have come to talk about over the last few years even before Sanders started running. I think she was going to need to talk about it either way.

But in other ways she made other distinctions with him — at times trying to suggest he was too focused on just inequality and Wall Street and not on the other issues important to Democrats, like racial discrimination and gun control. Some of it was adapting to his candidacy by echoing him, and some of it was pushing back against him.

I'm just not sure Sanders really forced her to make any concessions that she wouldn't have made otherwise. He never was quite enough of a threat to her actual nomination to really require her to change course in a fundamental way in this campaign. And I think a lot of where you see his influence is on the edges — in the rhetoric and the approach in the primary. And I'm not sure whether we'll see a substantive lasting effect of the Sanders campaign.

It may be that after the conventions, the Clinton people feel they have a big problem appealing to Sanders voters and have to revisit his issues. But absent that, it's not clear to me that there's been a large-scale effect on the party in general.

JS: What if we look at something like campaign finance? Sanders was able to raise enough from his small-donor army to not suffer financially against Clinton and do so in a way that also redounded to his political benefit. Could there be a lasting lesson there?

DH: I think there's probably something to that. He showed that you can raise a lot of money from small individual donations without making nice with business interests within the party, and the Clinton fundraising strategy going back to the '90s was to sell themselves to wealthier interests as being somewhat business-friendly.

So Sanders does represent another path, and he was certainly much better-funded than most of his liberal insurgent predecessors. He showed that you can use the internet and publicity to raise an awful lot of money. That's certainly one place where future presidential candidates could change.

Why Hopkins thinks Sanders is nowhere near remaking the party in his image

JS: So when you try to make sense of what happens to the unbelievable energy Sanders has built up, and his massive support among young voters, where does that go? What happens to that movement if not to change the party?

DH: The question of what becomes of the Sanders campaign and the Sanders cause is a bit of an open one.

It may be that years down the road, we look back and see his campaign as the start of an increasingly vocal and influential left wing of the Democratic Party particularly dedicated to advancing large-scale, public sector solutions to problems.

But that requires some sort of momentum within the party that remains after the end of this campaign, and for this cause to be taken up by Democrats other than Sanders. It has to be adopted by some congressional Democrats and candidates in future elections to stay alive within the party — to pressure Democratic leaders to continue to advance those policies. I'm not terribly convinced that's going to happen, but that's what would need to happen.

There's a temptation to assume that everything new in politics is a harbinger of the future. But lots of things are dead ends: They rise, and they go away. There's no reason to believe just definitionally that Sanders represents the future of the Democratic Party more than anybody else.

JS: So why are so many commentators convinced that Sanders represents the party's future?

DH: Sanders is a new phenomenon compared to Clinton, and he has younger supporters, so people make that assumption. But you could have said that about George McGovern [who was also extremely popular with young voters] — and then he lost, and McGovernism was not where the party moved at all after that.

I would be very careful in assuming Sanders represents the future. If he represents the future, there's no inevitability about it. If people want a change from the Obama Democratic Party to the Sanders Democratic Party, that will require a lot of political entrepreneurship — and I'm not sure, at this stage, how that would happen.

I think it's far more likely that at this point Democrats decide they need to pay a little more attention to the base than they have been, and be a little bolder than they have been on economic inequality. But most Democratic politicians are not going to become democratic socialists, and they're not really going to sign on to the scale of the policy agenda and the scale of government activity that Sanders is proposing. I think there will still be a lot of resistance to that.

JS: Most of the arguments that Sandersism is the future of the party hinges on this runaway support among young voters. Do you have a response to that? How does his youth vote support (and young voters' liberalism more generally) not suggest that he represents the party's future?

DH: To conclude that the strong Sanders vote among the young demonstrates that "Sandersism" is indeed the future of the Democratic Party, we need to make a few assumptions.

One is that young voters are supporting Sanders over Clinton primarily because of his democratic socialist platform, not because young voters are naturally more attracted to a stylistically idealistic and insurgent candidate running his first national campaign over an opponent who has been in the national eye for 25 years and is closely identified with her party’s "establishment."

A second is that young voters who are in fact attracted to Sanders’s support for free college tuition and for universal, single-payer, no-deductible health insurance — two issues on which we might expect younger voters to hold a particular personal interest — will continue to hold those positions as they age, gain higher-compensation employment, and begin to shoulder a greater tax burden.

"There are not that many historical examples of a party being quickly transformed by anybody; it's really hard to do, even if you're the president."

And three: The overall turnout rate in primary elections is very low among young voters and rises with age, but we'd need to assume the "millennial" Democrats who are participating today are politically representative of the larger generation of Democrats to which they belong, who will vote in greater numbers in future elections.

It seems to me that each of these assumptions is potentially dubious, and No. 1 in particular is difficult to believe wholeheartedly. I haven’t done a comprehensive study of the topic, but I know of no survey evidence that shows that the difference between younger and older Democrats on substantive issues is anywhere near as large as the generation gap in support between Clinton and Sanders, which suggests to me that Sanders’s fairly remarkable appeal among the young is based on more than just policy.

Why Hopkins thinks Obamaism is still the future of Democratic politics

JS: Then what would it take for Sanders to actually change the policies of the Democratic Party? Do we have precedent for that kind of transformation? What would it look like?

DH: There are not that many historical examples of a party being quickly transformed by anybody; it's really hard to do, even if you're the president.

Obviously, Franklin Roosevelt and Ronald Reagan did — but it's tough to do. A party is a big, complicated institution containing a lot of actors who have different degrees of investment in the status quo. So it's a very ambitious goal to remake a party in the image of a single candidate — you need to build a faction within the party, and the faction can start to exert pressure and build influence and move things in its direction policy-wise.

Two historical examples are the rise of the conservative movement in the Republican Party and the transformation of the Democratic Party on civil rights, which started with factions within the party that got strong enough that they could push the whole party.

Sanders doesn't lead a faction — he's really a Lone Ranger in a lot of ways. He doesn't have a lot of Congressional allies; he doesn't have a lot of interest group organizations aligned with him; his institutional ties within the Democratic Party are incredibly tenuous because he hasn't been a member of the party. So he needs some sympathizers to take up the banner.

JS: CNN today quoted Former Pennsylvania Gov. Ed Rendell saying that Sanders may have moved the needle "from 5 to 9" on the liberal scale, and that it will soon go back down. Do you think he's just wrong about that?

DH: I don't think there's any doubt that if you look at the Democratic Party today compared to the Democratic Party in the 90s that there has been a shift to the left — there surely has been, and the legacy of the 90s has been a burden for the Clinton campaign. Sanders is directionally consistent in a larger historical scope with where the party's been going.

But I think the key for understanding the future of Democratic politics is still Obama. Obama has shown you can win nationally as a Democrat not as a liberal crusader, but not as someone who takes on the left of the party to prove to the swing voters that you're not a liberal, either.

It seems like he will go down in history as the key figure in current Democratic Party politics — he showed how the party's new demographic coalition could come together. If you want to talk about the future of the Democratic Party, that's where it is — a future that's not as dependent on white southern voters and much more dependent on non-white, non-Christian, and well-educated metropolitan voters.

It seems to me that is the key shift — Hillary is running not as a 90s-era Bill Clinton Democrat but as an Obama Democrat, and she won. That suggests to me that Obama’s version of the party is likely to stick around for a while.

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