"Our U.S. democracy is the oldest and the most vulnerable. " In response to Reply #1
And our country the most valuable. To greedy schemers, we are an apple at it's ripest. This is what comes from having three presidential elections decided by electoral college and not the popular vote. 2000, 2004 and 2016.
A quick fix? Increase the number of representatives in the House of Representatives to their true value. That can put a stop to the "won the electoral college, but lost the popular vote!" nonsense. And it's fairly easy to do. No constitutional convention required or any of that. But a democrat majority in the House would be required.
Other than that, we need a major overhaul. Really. Long overdue. One of the things I would overhaul? Get rid of the US Senate. The world is too modern for such an old rusty anachronism as the US Senate.