The local board of canvassers finds fraud and they don't certify.
The USSC finds massive fraud but takes no further action.
The state legislators see the uncertified votes, and the SC decision, and they don't assign electors.
Neither candidate gets 270 electors.
That leaves it to the House to vote, one vote for each state delegation and Trump wins.
With all of those people involved, who would the left blame??
As you say, there's a good way to pass the buck.
This question has been covered. There is no shortcut.
Having legislatures refuse to appoint Electors will LOSE THE PRESIDENCY. This does not work. The reason is the Constitution says the vote among state delegations in the House takes place “immediately” but that word is not defined. Pelosi can simply no schedule the vote. Pres and VP term expires Jan 20 and she becomes president.
That vote can be held up forever by Dems in the House, immediately or not, and the USSC will never interfere with the process of Congress.
So forget that. The only winning maneuver is Legislatures — and then are Republican — have to conclude there is so much uncertainty and Trump/Biden only differs by a small number of votes in their state .. . they will use their own best judgement in appointing Electors, and that will be for Trump.
The Electors vote in their state (the “College” is the collection of all of them in their own state, there is no trip to Washington for themm) and an official document from the Legislature is sent to the President of the Senate (Pence). During a joint session he reads the votes and a sum is computed.
Votes can be objected to by any member of Congress as long as their is a second (this happened in 2000). Debate takes place and the presiding officer rules on the objection.
Done.