When the NDP was elected back into power in Manitoba the province was in excellent economic health. The PC's had finally balanced the provincial budget and the economy was booming. What put the NDP back in power was the union vote (here in MB 50% of the population are employed by some level of government or crown corporation and thus a union member) and the fear mongering about cuts to health care (which the PC's were forced into at the time as were provincial governments of all politcal stripes, by the federal Liberals slashing transfer payments to balance the federal budget).
Since then the provincial NDP government has spent and borrowed us into the crapper while breaking the law (the PC's had made passed balanced budget legislation), raping Manitoba Hydro of heir profits to support their spending and eventually changing the law so they could continue to run deficits.
Ok, I looked up the elections of Manitoban governments. The last time the PC were in power it was during the Trudeau years of Liberal government, which was a period of economic stability. After the conservatives took over federally, the Canadian economy declined, and it is during that period that the NDP were governing and it is against that backdrop that Manitoban economic performance has to be measured. But, in spite of what you call mismanagement and in spite of the recession and economic downturn over that period in the country as a whole (which, btw, will hit provinces like Manitoba the hardest), the NDP still managed 4 successive re-elections.
Btw, Manitoba Hydro is a crown corporation, which means that it belongs to the government of the province. If it makes profits, those are returned to the owners or invested. Since the government is the owner, any profit generated that is not going to be used for capital investment (not really needed, since the government would provide cash for large capital investments anyway) is going to be returned to them. Most private corporations work that way, why shouldn't a crown corporation?
Unless you have some sort of windfall income, pretty much all governments would (and should) be running at a deficit in economic times like these.
The problem is, during economic good times, such as in the 90s, they should be paying down the debt with surplus. Instead, they choose to "balance the budget" through various mechanisms, and parties of all stripes do this. The issue in Manitoba is that the PC created an economic condition that was exceptionally vulnerable to the effects of recession, and that is what Manitoba is paying for now.
It is different at the federal level, because the Liberals created policy that was less sensitive to the effects of a downturn, so when the Conservatives came to power they had much more leeway when the recession came.
The PC can't fix Manitoba's problems, because the structural basis for those problems were largely created by PC policies in the first place.