Both the Conservative and Liberal parties have declared themselves victorious over the recent Trudeau attack ads but the real winners of these ads have been the NDP.
Whether you like, or agree with, political attack ads they are a part of politics and are extremely effective, just ask Dion or Ignatieff. Both of them felt the wrath of the Tory attack machine and neither of them were able to recover from it.
A good attack ad highlights what the public's perception of them already is. Stephane Dion was seen as a weak leader that could not handle being prime minister hence the slogan "Not a leader." Michael Ignatieff was seen as a snobbish Harvard elite that was only in Canada to become Prime minister, which led to the catchphrases "He is just visiting" and "he is not here for you." All of these attack ads defined who Dion and Ignatieff were because the public already believed that about them, the conservatives just cemented this as their defining point.
The above reason is why the conservative attack ads are being so effective towards Trudeau, they are highlighting that he is inexperienced, unprepared, and as the saying goes, "in over his head." All of which is exactly what the public already felt about him. The effectiveness of the ad is why Trudeau and the liberals are losers when it comes to this ad.
Even though attack ads are part of and effective in a democracy they are highly unpopular and looked at as cowardly mudslinging. Outside of the Conservative base, these ads are being perceived as a cheap trick and dislike towards the conservatives continues to rise. For this reason the conservatives are also losers of this ad.
The NDP however are benefiting greatly from having the conservatives attack Trudeau. These ads allow the NDP the luxury of not spending money on, or bearing the negative condemnation that comes with running attack ads. Moreover the NDP benefit from the actual attack that the Liberals and Trudeau are taking because attack ads do work.
Every party can claim victory from these ads but the reality is the NDP has the largest victory to claim.