How can other Republicans knock Trump out of the lead?

Just hours after former President Donald Trump pleaded not guilty to federal charges of mishandling classified documents, the defendant pivoted back to the candidate. 

First, he stopped to press the flesh with supporters at a Cuban café and later revved up the crowd in Bedminster, New Jersey. 

A master at marketing, Trump – despite his legal troubles – still leads his Republican rivals in the polls. 

"Donald Trump has had approximately a third, say, 30 to 35% of the Republican electorate locked in. They are for him. They're not looking for anyone else. They don't want to vote for anyone else," explained Steve Adubato, an author and political analyst.  

It means the more Republican candidates in the race, the better the odds for Trump. 

So how can any other Republicans knock Trump out of the lead? 

Adubato said, "I would argue that there's only one way to do this, which is to take Donald Trump down in a public debate, going after him and doing it in a way where he looks weak, where he begins to back away, where he doesn't have that bravado." 

Candidates might not get a chance to do that because Adubato doesn't think Trump will participate in a debate if he's still ahead. 

Some in the pack think publicly offering to pardon Trump might lure his supporters away.  

Even though Trump appears to be using his legal battles to his advantage, the strategy could easily become a liability.