I think it might actually be possible indeed. You'll need to determine first the type of programs with which you'll be earning, be it the HubPages Ad Program, Amazon, eBay, or Google Adsense affiliate programs. However, whichever you choose, you'll need to make sure that those hubs of yours get a considerable amount of traffic. Therefore, you can't simply publish multiple hubs that won't likely draw traffic and expect to earn a dollar a day. I, personally, am struggling with this, too, I have yet to experience earning a dollar a day publishing articles on HubPages.