I really do not look at Steve Lonnegan as the equivalent of a Ralph Nader or Pat Buchanan and I will tell you why. Unlike Nader or Buchanan, Steve Lonnegan is actually a public office holder. Also, you must remember that Jim McGreevey, like Brett Schundler were also Mayor's. .
You're looking at it from the wrong angle. Lonegan is a 3rd party candidate that very clearly stands no chance. He's not even remotely close- the only 3rd party candidate to ever get close to anything was Perot back in 1992. Lonegan will get 5% at best, and all of those votes would be more than enough to get Schundler the win, so Forrester doesn't take the nomination.
Lonegan is right on the issues- but so was Pat Buchanan back in 2000 or 1996. He didn't stand a chance then, Lonegan doesn't stand a chance now. If this was Schundler vs. Lonegan, or everyone was running except Forrester, I can see the logic in a Lonegan vote, as one wouldn't exactly be putting a liberal into office by voting for Lonegan over, say, Schundler. But since Forrester is in this race- and worse yet, has the lead- any vote for a no-chance candidate is a wasted vote, one which hands even more power to Doug Forrester.