Be poles apart
Definition 1 of 1
Pro Tip 1/3Extreme Difference
The phrase emphasizes a very strong or significant difference between two things or people. 
On the issue of environmental policy, the two candidates are poles apart.
Pro Tip 2/3Not Spatial
It's a metaphorical expression; it doesn't mean physical distance, but figurative or ideological distance. 
In their approach to teaching, the old school and the new school are poles apart.
Pro Tip 3/3Negative Connotation
It often implies that the difference is seen as a barrier to agreement or harmony. 
Although they're brothers, they are poles apart when it comes to politics.