Well in New Zealand you get 94 percent of the baby boomers voting while only 70% of the young 18-24. Considering that generation tends to vote conservative it means the left has an instant handicap to get over the line both in numbers AND turnout. Which is not too dissimilar to the US (perhaps by degree) when the left, thanks to redistricting, requires often up to 7% swing their way just to break even.