Early in my career, we used to give lip service to "internal communications." Those were the days when employees were extraordinarily loyal and would default to trusting their leadership.
You're stuck. You have an important problem to solve. You need consensus where there is none currently. These are all great opportunities to consider engaging an outside facilitator.
In Daniel Pink's book, "To Sell Is Human," he explains what he calls "Non-sales selling: persuading, convincing and influencing others to give up something they've got in exchange for what we've got." The role of today's executive has shifted from order-giver to "mover." Pink explains, "Moving other people to part with resources, whether something tangible like cash or intangible like effort or attention -- so that both get what they want."
One size never fits all.
Are leaders born or made? Yes they are. Just like all skills. Some level of talent is simply baked into our DNA at birth. However, most of the skills we need to excel in today's world can be developed and honed. Particularly when it comes to selecting the correct leadership style for each particular situation. No one style fits all situations.
"Begin with the end in mind" is one of Dr. Stephen Covey's Seven Habits of Highly Effective People. This approach applies directly to persuasive presentations.
When you are preparing to give a presentation, the key question to ask yourself is: "What do I want the audience to think, feel and do?" This powerful approach addresses the three components to effectively drive the recipients towards a "yes."