They NDP and Greens naively assume that BC's economy will continue firing on all cylinders, even as they work to kill billions of dollars in construction. However, when you consider the elevated economic, political and regulatory risks/uncertainties that they've created it's difficult to imagine why companies and investors would continue to invest capital in BC.  The prospect of being tax-targeted to fund NDP/Green promises is hardly appealing. 

Likewise, they hope to be successful in their all-out effort to kill the Kinder Morgan project with the false assumption that Alberta won't respond in kind and no broader long-term economic consequences would result.       

In the immediate term, Horgan and Weaver can fund their spending spree using the surplus they inherited from the previous government.  However these are long-term spending commitments that will be deficit-funded within a couple of years and there's no turning the ship after that because it'll be sinking too fast.