With the next round of Republican debates approaching, this one focused on the economy, it's a good time to take a quick look at each candidate and how they're doing. While Donald Trump still leads in most polls, Ben Carson seems to be strengthening. In several recent polls, he has opened up significant leads on Trump in Iowa. Former Hewlett-Packard CEO Carly Fiorina has faded from a brief stint in third place to single-digit support while political heavyweights Marco Rubio (senator from Florida), Ted Cruz (senator from Texas) and Jeb Bush (former governor of Florida) have leapfrogged her. Wednesday night's debate will focus on the economy. It will be broadcast live on CNBC, starting at 8 p.m. eastern time. Follow TheStreet.com and TheStreet on Twitter for live updates.