A whirl of developments in a quartet of cases in four separate cities encapsulate the vast legal quagmire swamping Donald Trump and threatening to overwhelm the entire 2024 presidential campaign.

But Monday's hectic lawyering was just a tame preview of next year when the ex-president and current Republican front-runner may be constantly shuttling between courtroom criminal trials and the campaign trail.

A day of legal intrigue brought revelations, judgments, disputes and filings in cases related to Trump's bid to overturn the 2020 election, the classified documents case, efforts to thwart Joe Biden's win in Georgia, and even in a defamation case dating back to Trump's personal behavior toward women in the 1990s.

It's already almost impossible for voters who may be asked to decide whether Trump is fit for a return to the Oval Office -- or at least to carry the GOP banner into the election -- to keep pace with all the competing legal twists and the scale of his plight.

A confusing fog in which all the cases blend together could work to the former president's advantage as he seeks a White House comeback while proclaiming he's a victim of political persecution by the Biden administration.

But the deeper his legal mire gets, Trump's rivals for the GOP nomination are getting braver in suggesting that his fight against becoming a convicted felon could be a general election liability. Trump's dominance in the GOP primary has been boosted from his criminal indictments to date. But the sheer volume of cases unfolding alongside his campaign is increasingly daunting.

Even after three indictments, investigations into Trump drive forward

In Washington, Trump's lawyers just beat a deadline to file a brief in a dispute over the handling of evidence ahead of a trial in the election subversion case, and accused the government of seeking to muzzle his voice as he runs for a new White House term.

In another glimpse into the breadth of special counsel Jack Smith's investigation that could prove troubling to the ex-president, CNN exclusively reported that Trump ally Bernie Kerik, the former New York City police commissioner, met Smith's investigators for an interview on Monday. The discussion focused on what Trump's former attorney and Kerik's associate, Rudy Giuliani -- otherwise known as Co-Conspirator 1 -- did to try to convince the former president he actually won the 2020 election. The question will be a key one when the case finally comes to trial.

Trump's tough day in the courts had opened with a judge in Manhattan throwing out his defamation counter suit against E. Jean Carroll, which he did in stark language that recalled the ex-president's loss in an earlier civil trial in which the jury found he sexually abused the writer.

Then, in a surprise move in West Palm Beach, Florida, the Trump-appointed judge who will oversee his classified documents trial asked lawyers for co-defendant Walt Nauta to comment on the legality of prosecutors using a Washington grand jury to keep investigating. The fact the probe is still active despite several indictments is hardly a good sign for Trump. And Judge Aileen Cannon's move revived debate over whether she was favoring the ex-president's team following criticism of her earlier handling of a dispute over documents taken from Trump's home in an FBI search.

There were also new signs in Atlanta that indictments could be imminent in a probe into efforts to steal Biden's election win in the key state, as it emerged that ex-Lt. Gov. Geoff Duncan, a Republican and CNN political contributor, has been subpoenaed to testify to a grand jury.

All of this frenzied activity unfolding on one day represents just a snapshot of the complex legal morass now surrounding Trump. It's just a taste of the enormous strain the ex-president is about to feel as he campaigns for a return to the Oval Office. The crush of cases will also impose increasing financial demands. Already, Trump's leadership PAC has been diverting cash raised from small-dollar donors to pay legal fees for the former president and associates that might instead have gone toward the 2024 campaign.

In several of the cases on Monday, there were signs of the extraordinary complications inherent in prosecuting a former president and the front-runner for the Republican nomination. Judges, for instance, are faced with decisions that would normally go unnoticed by the public in the court system but that will now attract a glaring media and political spotlight.

And while Monday was notable for a head-spinning sequence of legal maneuvering, it did not even encompass all of the pending cases against Trump. He is also due to go on trial in March -- in the middle of the GOP primary season -- in a case arising from a hush money payment to an adult film star. As with his other indictments, Trump has pleaded not guilty.

For all his capacity to operate in the eye of converging storms of scandal and controversy, Trump's mood is becoming increasingly agitated. In recent days he has attacked Smith, the Justice Department, the judge in the election subversion case, former House Speaker Nancy Pelosi, Republican Senate leader Mitch McConnell, and even the US national women's soccer team after they crashed out of the World Cup on penalties.

Fear for witnesses over Trump's rhetoric

One of Trump's most incendiary posts on his Truth Social network was at the center of one of Monday's legal dramas -- wrangling between Smith's prosecutors and Trump's lawyers over the handling of evidence at the center of the forthcoming trial.

Prosecutors cited Trump writing on his Truth Social network on Friday, "If you go after me, I'm coming after you!" in a filing that requested strict rules on how he could use evidence that will be turned over to the defense as part of the pre-trial discovery process. Trump's lawyers had asked for an extension to Monday's deadline, but Judge Tanya Chutkan refused, in a fresh sign of her possible willingness to schedule a swift trial, which the ex-president wants to delay until after the 2024 election.

In its brief, the defense proposed narrower rules than those sought by prosecutors. Spats over discovery aren't unusual early in a trial process. But Trump's filing added insight into how his team will approach a case in which he has pleaded not guilty.

"In a trial about First Amendment rights, the government seeks to restrict First Amendment rights," the attorneys said in the court filing.

When it comes to Smith's indictment, Trump's lawyers are arguing that he was within his rights to claim the election was stolen. Smith's strategy is, however, apparently designed to avoid a First Amendment trap, and alleges that the criminal activity occurred not in what Trump said, but in actions like the ex-president's pressure on local officials over the election and on former Vice President Mike Pence to delay its certification.

The Trump team's filing went on to claim that the case was in itself an example of political victimization of their client, underscoring the fusion between his courtroom defense and his presidential campaign.

"Worse, it does so against its administration's primary political opponent, during an election season in which the administration, prominent party members, and media allies have campaigned on the indictment and proliferated its false allegations," the filing said.

In a Monday night order, Chutkan signaled she would hold a hearing this week on the dispute and told the parties to come up with, by 3 p.m. Tuesday, two options for when such a hearing could be held this week.

Any prolonged debate over the terms of the pre-discovery process -- let alone the many other expected pre-trial motions -- will play into the hands of the defense. Trump is showing every sign that part of his motivation in running for a second White House term is to reacquire executive powers that could lead to federal cases against him being frozen. The timing of the January 6, 2021, case, and any potential conviction, is therefore hugely significant with a general election looming in November 2024.

Trump has called for the recusal of Chutkan, who was appointed by former President Barack Obama. His legal team has called for a shift of trial venue away from the diverse US capital, potentially to West Virginia, one of the Whitest and most pro-Trump states in the nation. These pre-trial gambits are unlikely to succeed. But they help to create extreme pressure on the judge and to build a case for Trump supporters that the legal process is biased against him -- a narrative that could provide especially inflammatory if he is eventually convicted.

Trump's rhetoric about the case has raised some concerns about the possibility of witness intimidation -- especially as some of his supporters who were tried for their part in the mob attack on the US Capitol on January 6, have testified that they were spurred to action by his rhetoric.

CNN observed increased security around Chutkan on Monday. Security is also increased around the Superior Court in Fulton County, Georgia, where a decision is expected in days on whether to hit Trump with a fourth criminal indictment.

Trump's legal plight reverberates in 2024 campaign

Any normal political candidate would have seen their political ambitions crushed by even one of the cases in Trump's bulging portfolio of legal jeopardy. It is, however, a sign of the ex-president's extraordinary and unbroken hold on the Republican Party and its voters that he is still the runaway front-runner in the primary.

But one of his top rivals, Florida Gov. Ron DeSantis, is slowly becoming more willing to criticize Trump publicly, after being cautious about alienating Trump supporters who feel the ex-president is the victim of a political witch hunt. DeSantis told NBC that "of course" Trump lost the 2024 election, as he blitzes early voting states New Hampshire and Iowa and makes the case that the ex-president's legal exposure is a distraction the GOP cannot afford if it is to oust Biden from the White House after a single term. It may seem absurd that DeSantis is risking his political career by stating the obvious truth about the 2020 election, but Trump has made signing up to his false reality a test of loyalty among base voters.

And Pence, who rejected Trump's public pressure to thwart the certification of Biden's election -- a scheme at the center of Smith's case -- indicated over the weekend that he may testify in Trump's trial if required to do so by law.

The spectacle of a former vice presidential running mate testifying against the man who picked him for his ticket would be an extreme twist even in the Trump era of shattered political conventions.

Thanks to Trump's unfathomable and widening legal nightmare, nothing about the 2024 election is going to be anywhere near normal.