It means: "Those who are late have to work much harder than the others to achieve the same goal within the time limit"
Explanation:
The idea behind it is that if you want to finish work or accomplish the same as the others in the same time limit, you must start to work at the same time as the others. If you start late, you're either have to put in much more effort or stay later at night finishing what you could have done earlier.
The Declaration of Independence, which officially broke all political ties between the American colonies and Great Britain, set forth the ideas and principles behind a just and fair government, and the Constitution outlined how this government would function.
