Why does Trump insist on trying to convince people that the election was rigged?

In every state, the legislature adopts the election code.  But that election code is subject to the state constitution and judicial review.  

Equally important, that election code delegates to election boards, secretaries of states, and county officials the responsibility for making the day-to-day decisions of running the election which includes things like location of the precincts, review and acceptance/rejection of absentee and provisional ballots, etc.

The only unusual thing about this election was the number of cases filed before the election seeking to clarify ambiguities in state election laws.  

Otherwise, the election was mostly normal.  Yes, you had some local glitches, but that is not unusual and is why you have a canvassing process which is designed to catch and fix those glitches.  There is no state where the number of alleged glitches made a difference in the outcome as has been admitted by the Trump campaign in court.  

So when >3K voted in Nevada but they are on the National Change of Address database so they couldn't vot6e in Nevada that's not a sign of Voter Fraud ?

Or when Ilhan Omar's workers are riding around in his car withe >300 Mail in Ballots, that's not a sign of Voter Fraud ? When people in Arizona were given Sharpies to mark there ballots, but the ballot reader only reads Ball point pen That's not fishy ?

Let's just use ID's when voting ! Let the pollsters and Trumps Team Election officials

verify the votes!  Trump is the one asking the Judicial Branch to look at the Election results !!!  The Media and DEM's want to brush it under the rug as quickly as possible!

You're absolutely right, it's only the stupid people who know nothing about elections that it wasn't obvious to on Nov. 3rd when the counts stopped in ONLY the battleground states near midnight when Trump was up by thousands of votes then magically lost in hrs due to ballots from nowhere marked 100% Biden. Yea, the moron who couldn't find his way out of his basement for more than half the month leading up to election day came on like gangbusters right? LMFAO!

LOL.  The Democrats spent four years trying to convince people to believe in Russian interference in the 2016 election.

This just show how many Americans are totaly brain Washed !

When DEAD people start voting !

When people who moved out of state are voting!

When ilhan Omars guys are explaining how they Harvest mail in ballots !

When Polloing places send the Republican poll workiers home , the get car loads of Biden Ballots......

Even the brain dead people can figure out that So things know right here.....

But here you are .....

Here's your sign !

Governors, election boards, state secretaries, even some local mayors, all changed election laws leading up to the election, in multiple areas. Federal law states that all changes must go through the state legislative system.  In that respect, the election was flawed, rigged, whatever words one wishes to describe changing the rules, in the middle of a game.  Trump's challenges will not change the outcome, but they may stop these things from happening in the future. 

He is in denial.

Being perceived as a loser conflicts with his brand. In his eyes, his brand can't be wrong. So there must be nefarious actors responsible for his election loss. It makes logical sense, no?

One of two reasons.  First one would be that Trump's ego is so inflated that he mentally cannot handle that he actually lost and so his brain is supporting his delusions that it must be from fraud.

The other possible reason would be that he plans to continue this conspiracy line once he is out of office, and plans on making money from selling it to the media, possible even having his own radio or TV show.  He is a showman, and a snake oil salesman, so he might be working up the crowd for his future sales.

You seem pretty worried.