It's a critical year for Donald Trump.

Despite 12 months of unprecedented chaos, preening, insult, foment and brinksmanship, and his public support being the lowest of any modern U.S. president just a year into his term, most of the Republican Party and working-class base, which helped elect Trump, is still behind him.

In their relationship with Trump, Republicans clearly believe that "the ends justify the means." They've traded acquiescence on racism, xenophobia and support of a Senate candidate accused of child molestation for a once-in-a-generation tax cut for one-percenters and corporations, gutting of environmental, health and safety regulations and right-wing judicial appointments. How far the party of Abraham Lincoln, who as president freed the slaves and called for national unity in the 1860s, has fallen.

Meanwhile, workers hurt by continuing fallout from the 2008 economic crisis birthed by Wall Street, the financialization of the economy and globalization still cling to the hope that Trump, who packed his administration with Goldman Sachs alumni, billionaires and free-market fundamentalists, will carry out his pledge to help working-class America, even as he exploits their grievances by scapegoating minorities and immigrants.

But the continuation of this support will depend on how long Republicans find the ex-reality TV star the "useful idiot" and his base sticks by him.

That could collapse as a result of the November midterm Congressional elections, the outcome of the investigation into alleged Russian interference in 2016 -- and if there was any Trump campaign collusion -- and a recession in an economy already due for one.

Already, Republicans stand to lose the House. Opinion polls, recent state and by-elections, and the traditional experience of the president's party in midterms underscore that possibility. A split Congress would mean only bipartisan legislation would pass -- unlike the tax bill, which was passed with zero input from Democrats.

And remember, with impeachment, the House acts as a prosecutor when deciding to indict the president or not for "high crimes and misdemeanors." The Senate then serves as a court to determine to remove him or not. An additional loss of that chamber would likely mean the end of Trump's presidency.

A divided legislature, impeachment or cratering support, or any combination thereof, would add to the chaos, making it more difficult to deal with domestic problems and foreign policy conundrums like North Korea. And a frustrated Tweeter-in-Chief might lash out not only with 280-character blasts but also with a military excursion to distract the public and bolster his support.

Moreover, working-class America may turn against him, as some already have, once it's clear that the tax cuts and red-tape cutting have more to do with Wall Street than Main Street. Indeed, in 2016, Kansas voters threw out Republican trickle-down proponents in the state legislature after massive tax breaks, similar to Trump's, led to slashed school and infrastructure budgets, rather than promised growth and higher tax revenue.

Nonetheless, the Democratic Party could still screw up like they have over the past two decades.

It ran a flawed and out-of-touch candidate against Trump in 2016. And there are notions today of running Barack Obama's vice president Joe Biden or Oprah Winfrey -- another TV-star cum billionaire, albeit an African-American, self-made woman -- against him in 2020. That would be more of the same -- or gross inexperience -- at a time when the country is grappling with inequality in income, wealth and opportunities, despite rosy indicators and nearly nine years of economic expansion. Worryingly, in 2016, for the second year in a row, U.S. life expectancy dropped, bucking the trend for developed countries. Contributing to that was an opioid-overdose crisis fueled by economic despair and easy prescriptions.

Still, what is clear is that Trump is a running tragedy for America and the world. And 2018 could be the year that hastens his departure.

(James Simms is a Forbes contributor, freelance reporter and television and radio commentator in Tokyo and is a former Wall Street Journal columnist and former Scripps Journalism Fellow at the University of Colorado.)