Can Qualify for a Clearance if I had a felony Conviction and credit issues>

I have been a Sr. Technical Writer/Business Analsyt for over 12 years but have never applied for jobs paying more money because of clearance issues. I’ve always thought that if you had a conviction (mine over 15years ago) that you would be looked over. Because of this economy, I’ve had unpaid bills that have affected my credit rating. Can a competent writer/analyst still get cleared if you had these issues in the past? Any advise would be appreciated. I really want to take the next step but don’t know if I’m wasting my time.