It’s certainly a brave new world we’re living in these days. Back in 2016, Donald Trump set off a barge-full of booming red, white and blue fireworks all over the U.S. and won the White House to everyone’s surprise. Including his own. Not to mention, the GOP won control of both houses of Congress, 33 governorships and 32 state legislatures as well.

But the Republicans shouldn’t get too comfortable. Because irrespective of Trump’s victory, they need to remember one small detail. He was not their Plan A. He wasn’t even their Plan B or C. Plan A, the usual assortment of stiff blue suits with frozen smiles failed miserably as Trump plowed through candidate after candidate like Godzilla demolishing Tokyo in one of those old 1960’s Japanese movies. And, in the end, after disposing of Hillary Clinton, he slipped in through the back door of the White House and became President of the United States while both the Democrats and Republicans slept soundly in their beds.

But Trump’s election, irrespective of appearances, is not necessarily the beginning of a trend or movement as you’ve probably been reading. Rather, it is quite possibly the end of one. The last gasp of the aging, Eurocentric, predominantly white, hierarchy in America. His message resonated loudly in 2016 for sure within the present makeup of the electorate. But that’s all changing. And looking out a few election cycles from now, there are two very powerful demographic forces coming together that are forming, as mariners say, the “perfect storm”. The passing of the generational torch from the Baby Boomers to the Millennials and the ongoing influx of immigrants from Latin America, Asia and elsewhere. When combined, this new demographic will ultimately tilt the balance of power to the Democrats for the foreseeable future – or maybe longer. And the Republicans are sailing right into its monstrous waves with no plan to defend against it.

In the U.S., the Baby Boomers, 53% of which supported Trump and the Republicans, are starting to cede control to the Millennials as they continue to age and their numbers begin to decrease through natural attrition. Approximately eight to ten million Boomers are expected to die by the presidential election in 2028 and roughly another eight million by the following election in 2032. That’s nearly 25% of the Baby Boomer generation in the next 15 years. This will ultimately prove to be insurmountable for the Republicans. Although the Democrats will suffer proportionate losses as well, the more liberal Millennials will fill their ranks as they are more in line ideologically with their parents. Already, they are tied with the Boomers as the largest generation in the U.S. and will easily surpass them by the next election. And if you want to look out further, according to Pew Research, by 2050 the Millennials will account for roughly 80% of the electorate.

So, for Republicans, these statistics should give them real cause for concern. As the number of Republican Baby Boomers shrink, it cannot be assumed that they will automatically be replaced on a one-to-one basis by younger Republican voters. Because their children, many of which are Millennials, have very different and more liberal views of race, gender issues, gay rights, foreign relations and the role of government in their lives than their more conservative parents did. They are not traditional Republicans and are breaking with the Party’s political machine. Accordingly, as time goes on, many of their votes will start to shift to the left. In addition, the ranks of the Democrats and Independents are still growing due to the influx of Millennial age immigrants, many of which will ultimately be granted citizenship and thus the ability to vote. And these new citizens are spreading out across the U.S. as well which, in time, will alter the Electoral College map. So as the base number of Democrats continues to build and the number of Republicans decline, a broad ideological shift will start to unfold and change U.S. politics for decades to come. America will transform itself from the traditional center-right ideology of the Baby Boomers to the center-left politics of the Millennials.

None of this was lost on Barack Obama who pushed for increased immigration for years. He understood the impact that immigrants would have on the country’s profile – and politics – beyond his presidency. So much so that the U.S. granted over 5,000,000 immigrants new citizenship during Obama’s presidency. And while not every citizen in the U.S. actually votes, historically, most new citizens tend to vote Democratic as they typically lean on large government programs and entitlements that the Democrats support.

So, to the Republicans, I ask you this: what’s your plan to stay relevant as the country around you changes? What is your message to these more ethnically diverse, liberal voters? Make no mistake, the message that got Donald Trump elected won’t work for much longer. Certainly, not with these younger voters. Much of the Republican platform is rooted in an ideology based on ideas from generations gone by.

So how progressive are they willing to become in order to have a chance at running the country in the years ahead? It seems clear to me that, to start with, they will need to dramatically broaden their philosophical tent from the standpoint of race, gender and age diversity. Positions on issues like immigration and international relations will need to mirror the shifting views of these new voters. And they will need to field younger, more diverse candidates who will appeal to these more culturally and socially diverse Americans.

I’m not looking to write the Republican Party’s eulogy prematurely. But Trump was a product of a moment in time. He was the exception, not the rule. And just as the Democrats had an extremely rude wake-up call when Trump won the White House, the alarm clock is about to go off for the Republicans too. I just hope that this time around, they don’t sleep through it as they did when Trump hoodwinked the entire Republican Party and became the nominee. Because if they do, they will be on the outside looking in for decades to come.

And Donald Trump could well be the last Republican president the U.S. has for a very, very long time.

Or, quite possibly, forever.