Editor's note: This is the third in a weeklong series of questions The Next Mayor is asking — and answering — of the current candidates' campaigns. Monday: Lynne Abraham's campaign. Tuesday: Nelson Diaz's campaign. Tomorrow: Anthony Hardy Williams' campaign.

Question 3: Doug Oliver, 40, plans to draw his support from among the largest since bloc of voters in the city: those aged 18 to 34.  Shouldn't this provide him with the base he needs?

Oliver may be drilling a dry well if he is counting on millennials to come out to support him -- or any other candidate, for that matter. These two age groups (as defined by how the Census Bureau breaks its age data) are huge. There are 193,500 men and women aged 18 to 24 and another 257,800 aged 25 to 34.

With a potential pool of 450,000 voters, these age groups could be a true power in the city. But, they have anemic participation rates: 70 percent of 18-to-24s are either not registered to vote or haven't shown up at the polls at all in the last five years. For the 25-to-34 age group, the figure is 41 percent.

With such large numbers opting out of participation, it leaves a core of 210,000 active voters -- people who have voted at least once in the last 10 elections.

The trick to getting them out? Have Barack Obama's name at the top of the ticket.

In 2012, when the president ran for reelection, 86 percent of the active 18-to-24-year-olds showed up to vote and 87 percent of the active 25-to-34s showed up.

Most of them didn't show up before the 2012 race and most of them haven't been seen since.

Members of these age groups are overwhelmingly Democrat -- there is a total of 171,000 active Democrats. If the past is any guide, only 60,000 will vote in the May primary for mayor.

With hardly any money and little name ID, even if Oliver was able to win 60 percent of the millennial vote, he would still be less than a third of his way to the magic 100,000 number.

Bottom Line: Oliver can't count on young voters to carry him into the mayor's office.

Tom Ferrick Jr., a former Inquirer reporter and columnist and the founder of the news site Metropolis, is writing regularly on the 2015 mayoral race for The Next Mayor.