Smooth,
Great questions you have posed here so let me answer them the best that I can (with a little help from my friend, Jefferson). In response to your first question concerning the bolded section in Jefferson’s letter to Madison, the answer is the latter “that legislators are not capable of exhausting ways of making ownserhip more equitable (due to the problems of inequality being so "enormous")”. Of course Jefferson is speaking mostly of the property ownership of land but again this must be taken in the context of Jefferson’s view that an agrarian society was ideal. Further down Jefferson notes that, “if for the encouragement of industry we allow it to be appropriated (speaking of land at this point), we must take care that other employment be provided to those excluded from the appropriation.” Basically what Jefferson is arguing for is that if we allow great inequalities of ownership to arise within society, it will be the duty of the legislators to ensure that these inequalities do not become “so far extended as to violate natural right”.
In response to your second question concerning the “founders” it is first very important to note that lumping all of the “founders” together as having the same thinking is a mistake in itself for like all of us, each of them had significantly different ideas about how taxation (and government) should be handed. If, on the other hand, you are asking what Jefferson’s view was on taxation then I think that his opinion was quit clear and speaks for itself.
Jefferson: to Madison. Paris, Dec. 20, 1787. Speaking on the proposed Constitution for the United States. “I like the power given the Legislature to levy taxes, and for that reason solely approve of the greater house being chosen by the people directly. For tho' I think a house chosen by them will be very illy qualified to legislate for the Union, for foreign nations &c. yet this evil does not weigh against the good of preserving inviolate the fundamental principle
that the people are not to be taxed but by representatives chosen immediately by themselves.”
The founders were not (as a whole) so much opposed to taxation as they were to taxation without representation. (It is actually somewhat ironic that the American public actually paid more taxes after the Revolution then they did prior to the King.)
So the real question here is, getting back to the topic of this post, are fees paid to the UN by the US government tantamount to taxation upon the American public without representation? I would argue that they are no more so then much of the taxation policies that our federal government currently has in place today. Why? Most of our tax code is decided with mere tacit consent of the Congress because the Congress has delegated its Constitutional obligation to governmental agencies and only intervenes when it is politically convenient to do so (also note here that nowhere does the Constitution, or for that matter most of the writing of our founders, give any power of taxation to the president, hmmm makes you wonder why he is always talking about it so much like he should be in control of it doesn’t it?). This in itself runs afoul of the ideals held by Jefferson (and other founders).
However, laying these concern aside for the moment and returning to the fact that Congress has been given the power of taxation (see Constitution, Article 1, Section 8, Clause 1, and the 16th amendment) and that the President has the power to make treaties (with the consent of 2/3 of the senate) and shall have the power to appoint Ambassadors (again with the consent of the senate) (see Constitution Article 2, Section 2, Clause 2) then I find the argument that fees paid to the UN amount to a taxation on the US people without due representation unconvincing. Our government has been freely elected (whining liberals about stolen elections be damned), our national leaders have chosen as a matter of foreign policy that the benefits to be gained by participating in the UN offset the fees we are asked (not required) to provide, therefore I am lead to believe that because our elected representatives have determined that it is in the greater interest of our country to participate in this organization, and any dues paid the UN, therefore, were paid as a result of this decision, then the American people have been given representation through their elected government. If the American people believe that this government has not acted in their best interest then they are free to remove its leaders from power and elect those who they believe would do a better job of representing them concerning the best course for US foreign policy.
(As an aside note: for those of you who are interested in learning more about our founders and what they believed I would recommend the following sight.
http://www.claremont.org/ The Claremont Institute is a “conservative” intellectual think tank that believes in returning American politics to the ideals of our founders. Many of my professors from my undergraduate studies are Claremont Institute Fellows and contributing writers to this forum ... thus where I gained much of my knowledge of this subject matter.)