If Topp really does have numbers putting him around 28%, he should release his whole poll (including second choices) for comparison!
He doesn't, that was explicitly the "results" of a phone bank.
Now Brian Topp certainly has his own scientific polls but they chose not to release any of those, which is of course his prerogative. Really don't know why he insists on trying to run as the frontrunner though. As a Mulcair supporter I'm fraught with concern about how coming out as the frontrunner today might put a big(ger) target on us.