I try to treat everyone with respect regardless of stature. The idea that respect must be earned from the get go is flawed. You can respect someone who you disagree with, who is less knowledgeable, less moral, less upstanding than you, it just takes concerted effort. Doing so is much more difficult than simply disrespecting someone you deem to be "below" you.
Edit to add: I also fail at this goal all the time. I need to be reminded to respect the homeless, respect the combative, respect the unreasonable. It's so easy to judge others rather than extending grace and understanding.
Edit 2: I often come across people asking for money on public transit and my immediate reaction in my mind is "weren't you asking me for money last week too?" as if one week was completely enough for a homeless person to figure out their whole life and find housing and solve all their other problems too. Smh at myself.