Opponents of the Ontario Liberals must be wondering what they have to do to win an election, because obviously they are not doing the right things now.

The latest proof was a Toronto by-election after the Liberals were caught repeatedly failing to protect taxpayers' money, but the Progressive Conservatives and New Democrats were unable to put even a dent in their comfortable majority.

The Conservatives have been repeating every waking moment before and since that the Liberals gave Ontarians a "summer of scandal," but they will need much more than catchy phrases to bring them down.

As the second biggest party and one voters traditionally support when they do not vote Liberal, the Tories appear to have the only chance, although small, of catching up to the Liberals in the election due in 2011.

Voters have virtually excluded the New Democrats from their thinking since they ran up massive budget deficits when in government from 1990 to 1995, although they have recovered and now offer some of the better ideas and more effective presentations in the legislature.

One guide to opposition parties' prospects is how previous opponents won government. When the Liberals won in 2003, voters were ready to replace the Conservatives under premier Ernie Eves, because they had had their fill of spending cuts, started by premier Mike Harris and continued by Eves, that weakened public services.

In opposition, Dalton McGuinty promised many changes in policies, including increasing the minimum wage and welfare benefits, which largely had been frozen by the Conservative governments, and more spending on health and education, which signaled a more compassionate approach to governing.

Harris won government in 1995 when a puff of wind would have toppled the NDP, but he was brimming with tempting policies, including cutting bureaucracy and income tax, eliminating deficits and putting stricter curbs on labor, which many felt held back business, all in an easy-to-read pamphlet, The Common Sense Revolution.

These suited the public mood at that time, although some had lost their appeal a couple of elections later.

The NDP under Bob Rae pushed out the Liberals in 1990 after premier David Peterson had lost popularity by calling an election a year early and putting too much effort into placating Quebec, when Ontarians were more concerned about jobs.

But the NDP always offers more policies than other parties, because its rank and file, unlike those of other parties, hammers them out in public at conventions and expects them to be in party platforms.

The NDP had policies for everything, including some it could not fulfill, such as public auto insurance. All these governments helped dig their own graves, but opposition parties also offered appealing policies.

This cannot be said of the current Conservatives.

The only policy new leader Tim Hudak stressed in the by-election was opposition to harmonizing the Ontario and federal sales taxes, but his case was weakened, because he was not sure he would kill harmonizing and some business-minded Conservatives support it.

When Hudak campaigned for leader, his most consistent theme was curbing the power of human rights tribunals, but he has been cautious not to raise this now, because most Ontarians feel the tribunals provide needed protection.

And his emphasis that he is a disciple of Harris would have won him many votes a decade ago, but not now. He also has said since that he wants to reach out to immigrants, but not how.

Hudak was handicapped because the by-election was forced on him when he had been leader only a couple of months and before he could put together a wide range of policies addressing current issues.

He will have difficulties finding popular new policies, because he has a record of being right-wing when this is not popular and, if he wants to appear more moderate, his problem is that McGuinty occupies most of the centre.

But the Conservative leader will need policies, because he is not going to win an election merely by reminding voters that he is not Dalton McGuinty.