Glad to see that after 3+ years people have the cajones to start diggin on Big ole' Swinging Dick.
POTUS knows that Pence would/could never be the one individual to make a clear determination of Fraud. There is a reason why Fraud has to be plead specifically and determined with a higher (albeit unwritten) burden of proof. The issue here is that no judge HAS ALLOWED any case to be presented with full evidence be given before a jury sufficient enough for reasonable finders of fact to determine that ANY Fraud has been committed. To expect ONE MAN to make such a determination WITHOUT hearing ALL the evidence directly from fact and expert witnesses seems completely unreasonable. What Pence MIGHT be able to do is determine that an alternative slate of electors presented by state legislatures (not the state executives) will be counted INSTEAD of the original slate presented from individual states.
Accordingly, I see the Pence tweet as yet another example of POTUS exhausting ALL OTHER OPTIONS to rectify this obvious sham of an election, which is what he is obligated to do prior to the use of his ultimate authority and power under the Constitution to do so.