Conventional campaign wisdom dictates that the surest strategy for success is to raise as much money as possible and then spend it all on television ads in the final weeks of a race.

A look at the spending already in this presidential campaign — President Obama dropped $38 million on TV ads in June and has spent $107 million on commercials so far — suggests that television remains king when it comes to politics.

And yet, the massive growth of the web, tablets and smart phones have already begun to cut into just how determinative television is in a campaign — as voters are now consuming much more of their information through this panoply of devices.

The good people at Google have put the numbers together in a single chart that tells the story of peoples’ political news consumption habits.

Here’s the chart (and click here to see a larger version):

Among the findings:

* One-third of people who have seen a campaign ad on You Tube have not seen the same ad on television.

* One-third of likely voters said they had not watched TV in the past week.

* Tablet ownership doubled in over the 2011 holiday season.

Nothing above means that computers, tablets or smart phones have displaced television as the primary vehicle through which people get their information about politics.

But what they do suggest is that we are in a time of rapid change in information delivery and that change is — and will continue to — force campaigns to deal with the changing consumption habits of potential voters.

TV will never disappear (or at least not for a very long time) as a powerful medium to convey information to voters. But, it will — in 2016, 2020 and beyond — transition to one of several ways that people get their information as opposed to the dominant one.