Unlike the Ontario Liberals and Progressive Conservatives, the Ontario NDP have fully costed their platform and they project running surpluses on their budget. They are therefore the only ones whose policies would NOT run up the debt. The PCs had a platform that made sense financially, but Doug Ford scrapped it by killing their plan to put carbon tax revenues into Ontario services. Idiotic, really, because carbon pricing is coming whether he wants it or not.
It hasn't happened in Ontario since the 1980s, but with all the weirdness of this election cycle including new electoral riding boundaries... yeah, many things can happen.
Horwath is now polling AHEAD of the incumbant in popularity. If left-leaning Ontarians want to stop Ford (and let's face it, that has to be our first priority): I say vote NDP.
Because even if he forms government with a minority of seats, Ford can do less damage than he could with a majority.