In the last week I have heard the following sentiment from two different people, "If they would give me the authority to make the changes I want to make, I could be successful." In other words, "I am currently not successful, and it isn't my fault. Other people are preventing me from doing what I know will work best. If those other people would give me unchallengeable authority, everything would work perfectly."
You should know that even leaders with unchallengeable authority are not effective using their authority alone. To be effective, they need to garner support from the people they hope will follow them. If they don't get that support, they can be successful for only a short while at best. Only if they are proven to be right, will others follow them for longer.
The same is true for you where you hope to lead. Only, one of the groups people you hope to get to follow you are the "other people" who are standing in the way of your success. You need to garner their support if you hope to get the authority you think you need to succeed.
Actually, authority is seldom a part of the equation for an effective leader. Effective leaders need to get support from the people they hope to lead, including those who have authority over them. It is a matter of selling your vision of success so that those "other people" have confidence in your leadership.
Don't let a lack of authority get in your way. Sell your vision by identifying the "other people" in your life and convincing them that you can help the team succeed with your vision. Don't forget to listen to them, too. Those "other people" may know something you have missed.