0%.
The president has NO authority to suspend either the process, or results, of an election.
The Constitution grants no such powers.
It would conceivably be up to Congress to pass a law that could attempt, in extreme circumstances, to suspend or reconfigure an election, but that likely wouldn't survive the immediate and expedited court challenges.
I've been following presidential politics for decades, literally starting before I was a teenager, and every election cycle it's been....
"Carter/Reagan/Bush/Clinton/Bush/Obama is going to CANCEL/INVALIDATE the results of the election and become dictator!!!!!!!!!!!!!!!!"
To see exactly how little people understand the concept of the workings of our government and its structure, one only needs to read some of the literally thousands of websites where people are screeching like howler monkeys about this.
Could, conceivably, a president, working in conjunction with Congress, pull off an Emperor Palpatine/Adolph Hitler move to get extraordinary powers in time of emergency and use that to catapult himself into permanent Dear Leader status?
Well, anything is possible, but given that it's NEVER happened in US history, even in the depths of the Civil War or the Great Depression or World War II, chances of it happening are, in my estimation, 0%.
While normally I would agree with you. With the Whitehouse this time around more or less publically accusing the president elect of colluding with a foreign power to rig the election; it makes me wonder if they think they can try to play games with the electors or try indicting Trump to prevent him from being seated. I think ultimately the likelihood is slim to none. However we have never that I recall had the current administration basically accuse the incoming one publically with having a foreign power influence the election for them. Combined with the electoral nonsense it just makes me wonder what they think the end game for them is. I have never seen either party as unhinged as the Dems are this time around.