The correct answer is the powers the constitution delegated to it.
During the development of the Constitution, the Anti-federalists were concerned about the size and power of the federal government. Many of these individuals were fearful that a strong federal government would become corrupt, just like Britiain's was before the colonists declared their independence. In order to prevent a tyrannical central government, the Anti-federalists proposed having the federal government only having the powers specifically given to them in the US Constitution.
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Do you know the context?
I suppose the quotation is stressing that the writer has put a lot of effort into getting their argument/grievances heard by the parliament, and that said parliament is 'tyrannical', implying that it rules without concern for the people or accountability to them. It seems that the quote may be a way of justifying some later action, essentially saying; 'we've tried and failed to do this in the proper way, so now we must be more forceful'.