Smooth transitions from one idea to the next is many times overlooked when a speaker is crafting their speech. Speakers think about the ideas of a speech and not on how to get from one idea to the next.
When an audience is confused as to whether it is one large idea or several smaller ideas badly joined together, the cause can be poor transitions. Think of a transition as a fulcrum between two ideas or more simply as a playground teeter totter. The transition acts as a balance between the ideas. If the ideas in a speech are being given to prove the main topic of the speech, the transitions will lead the audience to a logical consensus. Ideas are the building blocks for a presentation similar to a large wall. Each building block contributes to the final message in a speech. Transitions are the mortar that holds these blocks together.