Be pushing against an open door British verb phrase
If someone is pushing against an open door, they achieve their aims easily because many people agree with them or support them.
They thought I was pushing against an open door in getting the scholarship, but the fact is I tried my hardest to achieve it.
Persuading his mom to give him money is like pushing against an open door. She will give him anything he wants.
The polls show that Jane has more than 85 percent approval rate. It seems like she is pushing against an open door with the election.
The verb "be" should be conjugated according to its tense.
The idea of the idiom comes from the fact that you have no difficulty in pushing a door that is already opened.
hurt someone or yourself
If you try to carry that suitcase, you’ll do yourself a mischief.