A job posting has been put on the internet for the position I currently hold. Is that legal?

I am a retail store manager and I was recently approached by my supervisor and told that the company was not happy with my performance. It was suggested to me that I would be moved to a lower volume store and that a Regional Manager would be around in the near future to discuss my options. I have come to discover that my job and title are posted on indeed.com as an open position. This actually occurred before my District Manager sat down to speak with me.Nothing has been discussed with me regarding my future since that conversation. Are they within their legal right to do this? What options, if any do I have to combat this possible demotion? Our business has been down this year company wide so is it legal for them to pick certain individuals to demote based on performance when the company as a whole is down?