Bruce : "But I have noted that ONLY the action of Republicans ever causes any concern- Is it true that Democrats are ALWAYS perfect, and NEVER resort to using the rules to benefit themselves????"

That's not really so.   In past elections Democrats in some states, cities and counties have been accused (and sometimes clearly rightly so) of ballot box stuffing and other sorts of election fraud.   

The widespread election fraud concerns over the past 6 to 8 years, though, are of the sort that Republicans are much more likely to be involved in.   Low voter turnout usually favors the conservatives (as Paul Weyrich even admitted when addressing a conservative church group a few years ago), so Democrats (liberals, progressives) have little motive to undertake across-the-board voter suppression tactics such as registration roll purges or deliberately doing things to make voting take a lot of time and effort.
Plus lower-income voters tend to vote Democratic, so making voting lines long tends to disproportionately suppress Democratic votes.

The use of unverifiable electronic voting machines with proprietary source codes is also more likely to lead to pro-Republican election fraud, simply because the big corporations that own the voting machines and source code are usually owned and run by Republicans or by others who favor big business.   I have yet to hear of a voting machine company that's owned by pro-Democratic or progressive-leaning people.

Now, IF and when any party controls things like access to voting machines or the voter registration rolls or the vote counting in a given precinct, county, state, etc., corruption may well occur.   But when the vote count is transparent, there are usually checks and balances against fraud.

Today's election fraud seems primarily to take the form of voter suppression (which works against Democrats) and unverifiable vote counting by machines (which Democrats seldom control).