Democratic National Committee officials have said that picking a city to host the 2016 nominating convention will mostly be a "business decision" based on logistics and money.

Convention organizers almost always say that.

Yet presidential politics is the whole point, so electoral strategy has to be at least a back-of-the-mind consideration this week as a DNC technical team comes to Philadelphia to inspect the layout of the Wells Fargo Center, ride the subway, and talk to police commanders.

"There are practical considerations, but the parties often select a site to send a signal," said Costas Panagopoulos, a political science professor at Fordham University who has edited a book about modern conventions. "They can be powerful symbols."

In recent campaigns, both Democrats and Republicans have chosen sites they hoped would help carry a swing state, or to make a statement.

That's been the case this year, too. Republican officials liked Cleveland's assets but acknowledged they chose it last month for their 2016 convention because it is in the most fought-over state.

"As goes Ohio, so goes the presidential race," party chairman Reince Priebus said in making the announcement. No Republican has ever won the White House without carrying the Buckeye State.

Pennsylvania's electoral importance is part of the case Mayor Nutter and others will muster - arguing that Philadelphia would better position the party than the four other cities still in the running: New York City; Birmingham, Ala.; Columbus, Ohio; and Phoenix.

"There is no electoral math that will elect a Democratic president without carrying Pennsylvania," said former Gov. Ed Rendell, also the former mayor - and the party's national chairman for the 2000 election cycle.

In presidential elections, Pennsylvania has become a safely blue state - no Republican has carried it since George H.W. Bush in 1988. Might that argue against Philadelphia?

No, Nutter said, because Democratic victories in the Keystone State have been built on big vote margins in the city, and the "excitement" of a convention here would help drive voter turnout.

"Everyone knows that the key to getting to Pennsylvania Avenue is winning Pennsylvania, and most of that road is paved right through Philadelphia," Nutter said.

City leaders have yet to offer an estimate of the potential economic impact of a 2016 convention in Philadelphia, though backers assert it would be a substantial boon to business. Charlotte, N.C., which hosted the Democrats in 2012, said it got $91 million in direct spending, and an indirect ripple effect of $72.6 million more.

The DNC team is scheduled to visit Philadelphia on Wednesday and Thursday. The party will announce its decision late this year or early in 2015.

Each of the finalists offers political pluses and minuses.

Though the Democrats' chances of carrying Alabama are roughly zero, meeting in Alabama could highlight the civil rights movement - a touchstone of the modern Democratic Party - on the 50th anniversary of the Civil Rights Act of 1964.

New York City would not provide much political bump - New York is even more deeply blue than Pennsylvania. Yet Hillary Rodham Clinton, the front-runner for the 2016 nomination, represented the state for eight years in the Senate. It's home. The venue also would give the party a chance to highlight a new hero of the left: New York City Mayor Bill de Blasio.

A convention in Phoenix could mobilize the Democratic vote in a city that is 30 percent Hispanic. The state has typically gone Republican, though more narrowly in recent elections. A possible downside: Its proximity to the border with Mexico could put the focus on illegal immigration.

While electoral targeting is part of the calculus in selecting a convention city, the two parties have had mixed results doing it.

Philadelphia hosted the GOP in 2000, but nominee George W. Bush lost Pennsylvania.

Democrats put their 2008 convention in Denver, for instance, hoping to flip Colorado into their column and to appeal to the surging Latino population of the inter-mountain West. President Obama carried Colorado then and in 2012, and the party has become more competitive in the West.

Both parties got skunked in 2012. Democratic strategists chose Charlotte because North Carolina was getting more competitive, and they thought the convention could help Obama carry it - as he had in 2008. But four years later he lost the state narrowly to Mitt Romney.

And despite the GOP convention in Tampa, Florida went for Obama over Romney.

Over the years, nominating conventions have grown exponentially more elaborate in staging as their decision-making importance has diminished. Long before the gavel falls to open the quadrennial meetings, each party's nominee for president has already been chosen by primary and caucus voters around the nation. Conventions ratify those decisions and also the nominee's choice for running mate.

So - along with giving the parties a chance to wine and dine their biggest donors - the gatherings are essentially infomercials. Recognizing this, television networks have slashed the amount of prime-time coverage devoted to the affairs, and there is talk of shortening or even eliminating conventions altogether.

But the ritual survives, in part because it is a rare opportunity for the parties to make their cases directly to voters.

"Based on what they'll see on TV, they're not going to know whether the convention is in Brooklyn or Philadelphia or wherever," said Larry Ceisler, a longtime Democratic communications strategist in Philadelphia.

"Sure, you would get national news stories about Ben Franklin reenactors and Hillary Clinton downing a cheesesteak, but . . . I'm not sure politically it makes a difference."

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