Sen. Robert P. Casey Jr. (D-Pa.) speaks during a town hall meeting April 2 at Lackawanna College in downtown Scranton, Pa. (Butch Comegys/AP)

Earlier this month, Sen. Tim Kaine began the congressional spring break with a trek through Virginia’s southwestern towns and small cities.

The Democratic vice-presidential nominee in 2016, Kaine talked to college students in Ferrum and miners in Castlewood, places with about 2,000 residents each. All told, he did 13 stops in five days across a region not known for its support of Democrats, but that’s okay with Kaine.

“Presence is important,” Kaine (Va.) said in a brief interview. “You’ve got to go to these places.”

That adage about presence is one of the increasingly accepted lessons Democrats are heeding from the debacle of last year’s White House and congressional elections.

Throughout the last decade, Democrats pursued what was considered to be the most efficient strategy of winning in presidential and Senate contests — turning to technocrats who knew how to find their most loyal voters in cities and suburbs and drive up turnout from their base. It helped Barack Obama win two presidential campaigns and gave Democrats a Senate majority for eight years.

By last year, however, the party’s smart set — including Kaine’s running mate, Hillary Clinton — became so fixated on cranking up the Democratic base that it did not do enough tending to potential supporters in exurban and rural counties. That led to a cratering of support in those regions and opened a path for President Trump’s victory — and helped Republicans keep control of the Senate.

Some liberal experts argue that white-working class voters in places like Castlewood and small cities across the Rust Belt have abandoned the Democratic Party forever. But that viewpoint is losing credence among those who want to win. One of the leading liberal demographic analysts, who literally wrote the book on the issue, dismissed the idea that demography alone is destiny for Democrats.

“I think that’s a minority view at this point of the Democratic Party. I think most people have looked at the data. The real world has talked back, and I think people are now recalibrating,” said Ruy Teixeira, co-author of 2004’s “The Emerging Democratic Majority.”

Now a fellow at the Center for American Progress, Teixeira appeared last week at the sort of think tank debate that appears to be set up as a moderate-versus-liberal feud about the Democratic future. It was hosted by Third Way, a center-left outfit that has been critical of the party’s lack of appeal to middle-of-the-road voters.

Instead, Teixeira and Lanae Erickson Hatalsky, Third Way’s demographic expert, largely agreed that Democrats’ failure in 2016 was because of a historic drop in support from white working-class voters.

Teixeira and Erickson Hatalsky argued that Democratic victory in the future would require an all-of-the-above approach: increasing margins among minorities and urban professionals while winning back the millions of voters who twice pulled the lever for Obama and then backed Trump last year.

Without brining those voters back into the fold, Democrats could keep losing in the near term. “I think the question is not whether we should do this, but how exactly to do it, and I say, ‘Let the debate begin,’ ” Teixeira said.

It starts in places like Schuylkill County in Pennsylvania, southwest of Scranton, where there are just about 60,000 people who vote in presidential elections, a fraction of the more than 600,000 who regularly vote in Philadelphia. In 2012, Republican Mitt Romney won by 13.5 percentage points in Schuylkill, less than 8,000 votes. But four years later, Trump won by more than 23,000 votes, getting 70 percent to just 27 percent for Clinton.

In a state Clinton lost by 44,000 votes, that swing in Schuylkill became quite significant, especially as similar shifts were replicated in dozens of other rural counties.

One basic remedy that has taken hold among Senate Democrats is just to show up — go to these towns now, go early and show the few Democrats there that you care and let other voters know that you’re at least listening.

When the election season kicks into high gear in 2018, these Democrats will be much more focused on the dense population centers — like northern Virginia for Kaine and Philadelphia’s suburbs for Sen. Robert P. Casey Jr. (D-Pa.), both of whom are up for reelection. But when they do make the occasional stop next year in those rural towns, Democrats hope that there will be residual goodwill from the time spent in the same places this year.

In Pennsylvania, Casey does not need to win a majority in those places, he just can’t lose as badly as Clinton did. And he can’t rely entirely on Philadelphia’s huge Democratic lean.

Despite the myth of low turnout last year among minorities and liberal activists, Clinton performed better than Obama did in 2012 in Philadelphia, the four large suburban counties around that city and Allegheny County, home to Pittsburgh.

She lost the state’s rural parts. The same thing happened in Florida, which also had better turnout than in 2012. Clinton got the necessary votes in urban centers but then got swamped by Trump in inland counties.

Those results, and the ensuing criticism of her campaign, were a painful irony for her. In Clinton’s 2008 primary against Obama, the white working-class Democrats were the bedrock of her support. In 2016, she tried to rebuild the Obama coalition, losing those white small-town voters to Sen. Bernie Sanders (I-Vt.) in the primary and then, by even larger and decisive margins, to Trump in the general election.

The divisive question for Democrats is how to talk to working-class voters — what issues and which values to highlight.

Senate Minority Leader Charles E. Schumer (D-N.Y.) has hinted at a new, more progressive set of proposals that appeal to supporters of Sanders, whose populist economic message won converts among liberal activists and in small towns devastated by the decline of manufacturing.

But Erickson Hatalsky, from Third Way, warned that the Democratic brand is often seen as giving away “things” to different blocs of voters, deriding a Sanders proposal to make college education free at public universities.

“Doubling down on free college for everyone and extra things is not the way to do that. If that’s the problem with the Democratic brand, then things like free college actually make it worse,” she said.

“These things are actually pretty popular and pretty important,” Teixeira responded, explaining that Democrats need to add more policy muscle behind these ideas. “You need to open up a broader narrative about the kind of economic change you seek to bring to their communities that speaks directly to them and to the world they live in.”

For now, though, Democrats from the left to the center agree that the first step is Kaine’s “presence” theory — to at least show up in these small towns where some of them went missing in 2016.

“You won’t be able to have an organization of any kind in those counties until you actually put some effort into it and some resources,” Teixeira said, calling the “fundamental problem” for Democrats their almost -complete neglect of rural towns. “I think that’s got to change.”

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