The Triangle Trade brought labor for a <em>very</em> cheap price, much much cheaper than indentured servants. They also began to use the triangle trade instead of enslaving the locals because the natives knew their way around the land and could run away easily.
Using simple words, imperialism is a policy of certain country involving a will of extending its power by using any kind of pressure or force.
For example - In 1939 Nazi Germany together with Soviet Russia jointly invaded Poland, in the result, both countries extended its borders.
The democrats and republicans have influenced our current political system by sharing most of the same values and views with the American people. As their party members and those who associate themselves tend to lead more toward what the party wants.
