I am a non-American from Poland and have no trouble understanding lobbying along with the distinction between lobbying and outright bribery or more systemic corruption.

Also, a lot of lobbying happens without money changing hands. Politicians need professional bodies and local communites for a variety of reasons. From staging campaign stops through having experts to maintain a semblance of merit all the way to filling goverment positions and actually exercising power once they win elections. Thus these various groups gain influence.