Donald Trump is being backed into a corner politically and legally, with the Mueller investigation expected soon. How far will he go and can America's famed checks and balances withstand the coming storm?

It was a warm November evening on the gulf coast of Florida. President Trump was flying in for a rally two days before the mid-terms and the taxi driver taking us there was a Republican. “Government doesn’t always know best,” he reckoned. “The working man should decide for himself”. But he was a Never Trump Republican, worried about where this mad, bad presidency might end. In the next few weeks, his warnings and America's political instiutions are about to face a stress test like no other.

That night Trump helped rally his base; part of an effort that saved Florida for his party. But our driver was taking no joy from his party or its current leader. His concern was long-term; the damage Trump was doing to trust not just in politicians, but in America's storied system of checks and balances and what happens if the House of Trump comes crashing down, be it before or at the next election.

"He won't go quietly," he fretted.

This week the 45th president should have been delivering his second State of the Union address. The fact it will now happen next week, because of the longest government shutdown in America's history, is a sign of the country's woes. That it is merely one of many, shows how far the woes go.

In the past generation nearly every president has ended his address with the affirmation that the state of the union is "strong", Trump included in last year's speech. This year, truth be told the state of the union is as weak as I can remember it. Precarious, even. Americans are divided, not just in terms of their political views, but in terms of the facts they choose to believe. The next month or two will be a true test for the nation’s political institutions as multiple crises bear down on this White House.

Those crises are both political and legal. First, the politics.

The mid-terms weren't quite the “shellacking” Barack Obama or Bill Clinton received in their first-terms, however the result was a bigger blow to Republicans than most appreciated on election day. The GOP won some key races and increased their majority in the Senate. Many congressional districts took a long time to count, appeal and call. What became clear in the following weeks was that Democrats had picked up 40 seats, not the 30-odd anticipated on the day Crucially, Republicans lost quite heavily in the suburbs.

It was also noteworthy was how well Democrats did in the Mid-West. They saw off Republicans in the Ohio, Michigan and Wisconsin senate races, picked up House seats and won gubernatorial races in Michigan, Illinois and Wisconsin. 

You’ll remember that Trump only pulled off his upset victory in 2016 because he won Florida and all the mid-western states (except Ilinois). It will only take one or two of those to turn Democrat for Trump to be ousted in 2020.

While Trump has doubled down on what is proving a loyal base, the edges are fraying. The 35 day government shutdown has seen his approval levels drop into the mid-high 30s. One AP poll had him at just 34 percent. Independents are abandoning him and he’s enough of an anti-politician that he seems unwilling to pivot and concede policies as, say, Clinton and Obama did when they lost mid-terms.

Such political pressure would be enough to rattle most presidents, but that’s not Trump’s most pressing concern. He also has to worry about his own freedom, with legal challenges coming thick and fast. The Mueller investigation is drawing to a close and how Trump and his base react to that presents a real risk to American democracy.

We know that Mueller's investigations have ultimately resulted in at least 34 indictments or guilty pleas, six of those from former Trump aides. The charges include interfering in the election, lying to Congress and the FBI, and witness tampering. 

It's a staggering result for investigators. While they haven't yet shown evidence of Trump colluding with Russia over the 2016 election, they have shown in court documents that he lied during the campaign about his business dealings in Russia.  

But even Mueller may not be Trump's biggest worry. The claim that he violated campaign finance laws by paying off two women he had affairs with stems from New York prosecutors. 

All of this pressure is coming to a head soon. So how will a weakened and cornered Trump react? Or can might the Mueller report yet give him solace? The truth - and it's scary - is that most Americans have probably decided how they will react already.

One of the most dangerous facets of Trumpian politics, has been his erosion of America's institutions and those checks and balances. They have withstood all sorts of past presidential storms, but Trump and his media lackeys have schooled his base to distrust not just his opponents, but the the likes of the Justice Department, FBI, NASA and even election results themselves. It's party over country, ideology over facts.

So the stress test the US faces in the coming weeks is the toughest since Watergate. How far will Trump and his supporters go? What are they prepared to do to bounce back? The choices Trump, Republicans and their supporters make will tell us the truth about the strength of the union and will answer my taxi driver's questions. 

How much damage has Trump done and how much can he do? We are about to find out.