Question

Paraphrasing:

'Only armchair politicians are immune from committing mistakes.Errors
are inherent in political action.Those who are in the centre of political struggle, who have to deal with practical and pressing problems, are afforded little time for reflection and no precedents to guide them and are bound to slip up many times

Answer 1

Just easy chair legislators are safe from conferring mistakes. Errors are inborn in political action.Those who are in the focal point of political battle, who need to manage pragmatic and squeezing issues, are managed little time for reflection and no points of reference to guide them and are certain to mistake ordinarily.

Answer 2

This means that if one wants to be active in politics, one has to accept that sooner or later one will commit a mistake. Politics is a very fast field, and often decisions have to be taken without the time necessary to reflect on all the sides of the problem.

And my personal interpretation: this means that you shouldn't get discouraged but try to learn from your mistakes!