Earmarks lead to excessive spending. They are often made in secret or as political favors to a given member of congress' politically-connected donors and often go to projects that are completely unnecessary. Moreover, they are often inserted into bills so late in the drafting process that they are not subject to debate on the open floor.
Earmarks in politics do not lead to excessive spending and waste. Earmarks help to control the budget. If used correctly the earmarks will give the proper amount to each part that is needed and will actually help to cut down on wasted spending. Earmarks can be misuesd so they need to be monitored.