If Sam Katz plans to run for mayor as an independent I have a little advice for him: Once the ink is dried on the change of party form, he should get on his cell phone and start raising money.

The rules have changed from the days when Katz first ran for mayor as a Republican.  In 1999, when he nearly defeated John Street, he raised millions for that campaign by relying a lot of big donors, a Who's Who of Philadelphia who contributed in $100,000 chunks.

Those players are gone, banned from the field by Philadelphia's strict campaign finance law, which limits individual contributions to $2,900 and PAC-type giving to $10,900.

In 2015, you cannot raise $2 million from 25 donors.  It will take more like 500.

Katz has personal wealth, but he's no Tom Knox. He doesn't have $10 million to waste. Plus, there is the issue -- if I may dare to bring it up -- of his wife, Connie, who may not want to see the family's assets pledged to yet another mayoral campaign.

That said, there are two things I know about Katz.

1. He has wanted to be mayor of Philadelphia since he was eight years old or so and that fire still burns.

2. At age 65, the configuration of the Democratic field raises the tantalizing possibility that after the May 19th primary, there will be an opening for a well-known and well-financed third-party candidate.  It will be his last chance to fulfill his dream.

I understand the political calculus for Katz switching from Republican to Independent: the favorite to win May 19th is state Sen. Tony Williams, an African-American sure to capture a lot of the city's black vote.

Yet, Williams isn't an A-List candidate. Labor doesn't like him. He currently is seen as a one issue candidate (pro-charter schools). And though he still has three months to prove his worth, he could emerge not triumphant but scarred from a primary battle.

From a Katz perspective, it's better to prepare for any eventuality. The law requires that if you want to run in an election, you must change your registration 60 days before a primary.  By making the change this week, Katz meets that deadline.

Now, he can sit and wait for the outcome of the Democratic race.

I am not a betting man (it's the vice I don't have), but if I was, I'd lay down a $10 bet that, in the end, Sam Katz will decide not to run for mayor.

If I'm wrong, I'd contribute the $10 to his campaign fund. He'll need every dollar he can get.