The easiest way that I see (from a student's perspective) to deal with the situation would be suggesting a student power structure.
Simply put, it's going to be difficult for you to make any kind of power changes during the season. Putting a simple structure in for your team to create a hierarchy can make
everything more organized, not just chairman's. Furthermore, it will empower students to fill those positions, and really give each person a specific purpose and title (which everyone seems to like

).
I know that, for our team, the decisions for who presents Chairman's and what is said is almost completely student-controlled. Our Director of Public Relations is in charge of making those decisions, and final decisions are run by the mentor and explained to show a logical thought process behind it.
Frankly, if you begin to make your team run more like a business then people become accountable, and if people are accountable then logic will take precedence over preference. I know that our team would never have allowed someone who hadn't even been to a meeting present our Chairman's award, it is simply illogical to hope that the person will be able to absorb everything they need to in such a short period.
In short, by adding more structure to your team, it will take away some of the unnecessary stress from your mentor, as well as empower the students to stand up for their opinions. While it's not foolproof, it's a good step forward for
any team.
If you're looking for a less...formal approach, let me be the first to say that conflict solves nothing, unless it is done with
care and
tact. Realize that even though this mentor may have made a decision you disagree with, this person has made the effort to mentor your team, and still deserves your respect.