If you haven't seen the Hardfork process in action or if you were too new to understand at the time it was happening.
The way it works is when new code is presented the top 19 or 20 are considered the consensus witnesses. They decide whether or not to run the new code. When 17 Witnesses are running the code the blockchain considers that the "right" code. The others will upgrade. The point of influence is the top 20.
If you feel strongly about items in the code drop you can ask your consensus witnesses to make a clear statement for or against each change and whether or not they will adopt it. These discussions are usually done in Witness Channels, but as a voting stakeholder in Steem you have the right to ask.
If you want to have influence in how Steem moves forward review your witness votes and consider asking your witnesses for their position on up and coming changes. Make sure your witnesses reflect your point of view.
Also, it is a security measure that the witnesses feel comfortable that the code is good and will not break anything if launched, but I have seen many of them say, that they either trust SteemIt Inc or feel like they should be able to. Ultimately though it is the job of the Witnesses to keep our investment safe and our blockchain moving.
It is not my goal to sway anyone for or against changes that are being discussed, but I would like to see the community use whatever influence we have to participate in these decisions.
Usually, before a Hardfork is actually scheduled the code is released and there is a discussion, but by then the effort to code has already been spent. So, check out the SteemIt Blog and Witness discussions to find out what is coming down the pike and what it could mean to you.
This is why stake matters although alone none of us can control the witnesses besides maybe Freedom, the rest of us can gang up enough to make a difference. The more stake you have the more influence you have at the time of a highly debated HF.
Someone is going to jump in here and say that Freedom cannot be overpowered in the vote and although there is truth in that, it is not totally accurate.
Play the game like a Whale and use your stake to the extent of its influence.