I would argue that there was nothing hypocritical about President Cleveland’s veto of the Civil War pensions bill. I would say that it was very much in keeping with the values he tried to espouse throughout his presidency.
The only way I can see to argue that Cleveland was at all hypocritical is to link this pension veto to his efforts to reform the civil service. You could potentially make an argument that the veto contradicted Cleveland’s actions with regard to patronage.
One of the issues that was most important to Cleveland was the issue of good, uncorrupt government. He wanted to stop giving out offices based on partisanship. He also wanted to stop giving out pensions to all sorts of often fraudulent claimants who supposedly deserved pensions for their service in the Civil War. Cleveland vetoed the pensions bill because he felt it would give pensions to too many people who did not deserve them.
You can say that this was hypocritical because Cleveland did not always manage to adhere to his own values. Political pressures forced him to give in to some demand for patronage jobs. By the time he left office, many Republicans had been forced out of their government jobs and those jobs given to Democrats. You could say that Cleveland is hypocritical for giving in on this issue but then vetoing the pension.
I do not agree with this argument. I see the two as different issues. I also think that it is not hypocritical to give in on some political issues when you cannot win them. However, if you have to argue that Cleveland was hypocritical, this is one way to do so.