In the sense that the downsides are documented in the relevant scientific literature, sure. But popular perception of those downsides is very different. A whole lot of people think those downsides are a pack of lies: that cannabis isn't habit forming, that it doesn't make the average user lazy and complacent, that it doesn't increase the risk of schizophrenia, that driving under the influence of it isn't unsafe and is probably even safer, etc. The downsides are all "DARE lies" according to many of the people who think legalizing cannabis is worth it, who weighed the harms of criminalization against 'cannabis is literally harmless.'
(FWIW I voted to legalize it in Washington in 2012.)