College student not interested in going into politics anymore -- career switch?

Hey, first post here so I hope I'm doing this right.

I'm going to be a junior in undergrad next year, where I'm studying econ. By this forum's measure, my school isn't prestigious (we're horrible in rankings) but we have solid enough ties to Wall Street that quite a few of our grads go work for Goldman, JP, and a few other big firms.

I've recently decided that I have no interest pursuing a career in politics, public policy after graduation. Under normal circumstances, I'd tell myself that I'm overreacting and that I have plenty of time left, but given that most people break into the industry with internships their junior year and I have zero (really, none) experience in biz, I'm super concerned about my ability to get into the industry. I'm interested in working in ECM.

With no relevant work experience (I've interned for Congress and manage a political magazine), what should I be doing to set myself up for success by graduation? Fortunately, I'm an economics major (originally with the intent that it parlay in public policy) and this year I'm taking as many finance and industry electives as I can. I'm also taking some Wall Street Prep courses offered through SEO-U, but I'm having a bit of a difficult time trying to figure out how to demonstrate real interest.