> In Canada we used to have something called the "Per Vote Subsidy". Every political party got $2 of taxpayer money per-vote, per year.
We have that in the US as well. It has existed since Watergate (1976). In 2008, Obama became the first candidate to opt out of the system, despite an earlier pledge to use them (McCain, his opponent, did not - he used public funds).
Amusingly, Romney said that he'd prefer to use public funds, but the reason that he did not (in 2012) is that Obama did not, and he believed he couldn't be competitive against an incumbent president who would potentially be spending three times as much as he would be legally permitted to[0][1][2].
The system still exists, for any candidate willing to use it. Though I would not be surprised if McCain became the last candidate to take advantage of it. After 2008, no candidate who wants to be competitive will take public funds if their opponent isn't as well, and that's unlikely to be the case for both candidates in a race simultaneously.
[0] Accepting public funds comes with limits on total spending
[1] http://www.politico.com/blogs/politico-now/2012/08/romney-ab...
[2] And frankly, he was right - ultimately, he spent about the same amount as Obama did. If he'd been limited to the amounts that public financing would have restricted him to, he'd have lost in a landslide.