The most direct political imagery in Dylan's song is in the following lines:
Come senators, congressmen
Please heed the call
Don't stand in the doorway
Don't block up the hall
Imagery is description using any of the five senses of sight, sound, taste, touch, and smell. In the lines above, we can visualize the senators and congressmen holed up in the capitol. Outside the capitol, as other lyrics in the song show, the common people are massing and becoming like flood that will sweep in change, whether the politicians like or not.
The image of the congresspeople standing in doorways and halls suggests they are part of the group trying to block and prevent change. Dylan's song says that is not possible to do that, for there is too much force behind the movement for transformation:
There's a battle outside and it is ragin'
It'll soon shake your windows and rattle your walls
For the times they are a-changin'
The song was written late in 1963 and released in 1964. Because this was the time of the civil rights movement, and because folk music singers like Dylan were often supporters of that movement, some have argued that it is a song in support of civil rights. Others contend that its lyrics and themes are universal and refer to political change in general.