"In theory, in this type of political contest all a candidate needs is a simple majority of votes to win a political office. This is, after all, how it’s done at the state and local level."

Offices in some states do not require a majority of the votes cast to win - only a plurality of the votes. That includes the office of Governor.

"Sure, at the federal level we have the electoral college and it probably should be abolished, the bigger problem is that although the candidates with the most votes wins, it leaves everyone else who did not vote for the candidate disgruntled."

I disagree that the Electoral College should be abolished. The states just need a way to allocate the Electoral College Votes that ensures the candidate with the most popular votes wins the office: http://fairelectionadvocates.org/index.php/campaigns/campaign-menu

"Although we might consider redistricting, taking on gerrymandering, reforming who is allowed to vote, and/or encouraging the expanded use of mail in voting, what we really need is some form of or complete adoption of proportional representation (PR)."

Gerrymandering could be extremely reduced by converting single member districts to larger, multi-member districts.

"In general, PR, works this way: when you vote, you cast your ballot not for a candidate, but for a political party that has a list of candidates."

I prefer to vote for a candidate instead of a party. Implementing ranked choice voting single transferable voting could accomplish a form of proportional representation.