Building on this question: What procedures are in place to stop a U.S. Vice President from ignoring electors?, I am wondering what, if any, actions/inactions might be attempted by Trump, Pence, or other Trump loyalists to subvert the remaining steps toward Biden's inauguration and what effect they may have. It's been said that upcoming joint session presided over by Pence is a mere formality, where any attempt to subvert it would have no real consequence on Biden's inauguration. My question pertains to both the Congressional proceedings on Jan 6th and the inauguration on the 20th - what actions could conceivably be attempted, what guardrails exist to counter them, and what, if any, practical consequences might ensue? My question is predicated on the notion that "team Trump" shows considerable persistence and deep ingenuity toward keeping him in office (or denying it to a legal successor), so is intended to explore the robustness of the process forward of this point and any potential exploits open to mischief or worse.
As far as legal options go — and barring presentation of some actual evidence of widespread voter fraud — Trump's options are exhausted. There is no legitimate mechanism for Trump to stop either the confirmation by Congress or the January 20th inauguration. His allies can delay the first by a day or so (if they like) through legitimate objection processes, but such objections are destined to die in the House (and likely the Senate as well). And the January 20th date is set by amendment to the Constitution, so even if there were a valid approach to contesting the election, the best Trump could hope for would be to see Pelosi appointed president on that date.
Illegitimate options are more wide-ranging. Trump may be looking for a 'Reichstag Fire' moment in which he can declare a national emergency or insurrection, aiming to use emergency powers to suspend the transition. That would require support from the military (or some organized paramilitary group), and likely the cooperation of the Secret Service and other Federal law enforcement agencies. On a less dramatic scale, Trump might simply and stubbornly refuse to cede the office, thinking he can bully his way into another four years merely because the incoming administration would fear the conflict that would ensue from forcing him out. If he wants to go the dictatorial route he could try to have Biden, Harris, and others arrested, to prevent them from taking office. Of those three the second is the most likely, but all of them (if successful) would represent an end to US democratic institutions. But historically speaking, Trump has always been a conniver — a wheeler-dealer — not a fighter. I don't expect him to try the full-scale authoritarian moves himself, though he is certainly setting the stage for someone bolder down the line.
very quick answer, No.
All they can do is delay and grandstand for a few hours. It would take a majority of the house and senate wanting to overturn the election to do anything at all. It's actually a pretty scary proposition that is possible with just a majority of both houses and the president from the same party. That needs to be changed.