To respond to posts #46 and #47, I have to say that a republic refers to a government structure, whereas a democracy is an underlying political philosophy. These are two different things. Apples and oranges. They can be complementary, or not, as the case may be. A republic, in its simplest terms. is a structure that is not a monarchy. The U.S., France, Germany, Russia, etc., are republics while the U.K., Spain, Belgium, the Netherlands, the Scandinavian countries, Japan, etc., are monarchies. In other words, in a republic, you have a president rather than a king. Sometimes the president is powerful, as in the U.S., France, or Russia, and sometimes he's a figurehead, as in Germany, Italy, or Greece.
A democracy is characterized by free elections and popular sovereignty. In other words, the source of power is the people. This is different from ochlocracy, or mob rule. The United States has always aspired to democracy, the roots of which can even be seen in the Declaration of Independence. The 2nd Amendment itself is deeply democratic, referring as it does to the right of "the people." The entire arc of American history is a striving toward more and more perfect democracy, with the abolition of property requirements for voting, the extension of the vote to blacks and women, the popular election of senators, etc.
Simply having a republican structure does not guarantee popular rule. Dictators and tyrants can and do use republican structures for their own ends. (Hell, Venezuela is a republic!) Conversely, it's rare for a king to be a dictator in the modern age.