Editor's note: This is the first in a weeklong series of questions The Next Mayor is asking — and answering — of the current candidates' campaigns. First up: Lynne Abraham's campaign. Tuesday: Nelson Diaz's campaign.

Question One: How can Lynne Abraham win? Isn't she too old to appeal to voters?

It's been 40 years since Abraham earned the title "tough cookie" from Mayor Frank Rizzo, and it's been two decades since Abraham was first elected Philadelphia district attorney. To younger voters, she is an antique figure, the candidate of the past.

But, maybe the question people should be asking is: How can Lynne Abraham lose?

At age 74, she is a contemporary of the most powerful voting bloc in the city: voters 65 and older. They lived through the Rizzo years and many of them voted for Abraham when she ran four times for DA.

The U.S. Census tells us there are about 189,000 adults 65 and older in the city, and most of them are registered to vote. Now, let's cull this herd. A few are not registered to vote, while thousands are voters on paper but haven't turned up at the polls for five years or more. They number 38,600 -- 21 percent of the total in this age group.

That leaves the number of seniors who are active  voters -- ones who voted at least once in the last five years -- at 149,091.

Of this total, 121,000 are Democrats -- and many of them are very active Democrats. The over-65 crowd has the highest voter participation rate of all age groups. At 26 percent, it also has the highest percentage of Super Voters -- the folks who have voted in at least 8 out 10 of the last elections.

In a multi-candidate field, the sweet spot for winning the Democratic primary is 100,000 votes -- that's about what Michael Nutter and John Street got in multi-candidate Democratic fields in their first runs for mayor.

Abraham surely will not get all the senior votes -- they don't make decisions based solely on age -- but she can also tap into another, slightly younger, group of voters: those aged 55 to 64. These are folks who came of age in the 1970s. There are 108,200 active Democratic voters in this age group.

Winning 60 percent of the vote among these two age groups could yield 70,000 votes for the former DA, which is awfully close to the 100,000 she will need.

Bottom Line: Abraham will get a big boost from this crucial group of voters.

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.