You have to give them credit, the Democrats are showing that they can almost walk and chew gum at the same time. They have spent two months running an investigation and finally voted to impeach Trump in December and at the same time have been running a primary to choose the candidate who will face Trump in 2020.

Both activities share the same goal of cutting short Trump's days in the White House yet the success of either is highly uncertain. The Republican-controlled Senate will almost certainly acquit Trump. And despite a talented and historically diverse field of candidates, the primary race seems to be settling on four candidates: two older white men, former Vice President Joe Biden and Senator Bernie Sanders and younger white man, Southbend, Indiana Mayor, Pete Buttigieg and one white woman, Senator Elizabeth Warren. This group hardly represents the promise of the Democratic Party to be the party of diversity in the face of the Republican Party of old white men.

In fact, this was something the Republicans had vowed to remedy after Mitt Romney’s 2012 loss to Barack Obama. The U.S. is becoming more and more diverse and looking more and more like the state of California where white people are the minority. It was in 1980s that less white babies were born than babies of color in California and that same demographic milestone was passed in the whole of the United States in 2012. A democratic shift like this changes the electorate, as it already has in California where the Republican Party is unable to win state-wide elections and it is assumed that the same sort of reckoning will happen at the national level. It was unsurprising that after the 2012 election, the Republican Party released a report that concluded that they cannot continue to win by appealing only to white voters.

But this sentiment all that flew out the window in 2016 when the party chose Donald Trump as their presidential candidate who doubled down on the appeal to white voters. Yet he won, so he seemed to do so at the exact right time and place. There are two leading explanations for the Trump phenomenon: economic and cultural. While fears about the loss of factory jobs to technology and the shipping of them overseas is a big part of this angst that Trump has been able to tap into, the fear that many white people have that they are losing their place in the United States as they literally become a minority is very real and visceral. In fact, a data-based study on both sides of the Atlantic by Pippa Norris and Ronald Inglehart confirms that this cultural explanation is the stronger fit of the two.

So, in 2016, Trump’s not-so-veiled messages that appealed to white voters, especially white men were successful and may very well be again in 2020. Democrats, on the other hand, have seized diversity just as vigorously as Republicans have held tight to white voters. Barrack Obama’s election as their nominee in 2008, over Hillary Clinton, a woman, was the very embodiment of this promise to keep pace with America’s growing diversity.

Now, a highly winnowed field that started with more than 20 Democrats are fighting for the opportunity to try to dethrone Trump in 2020. This was the most diverse field of primary candidates in U.S. history: out of these twenty, five were women and three of them were originally considered frontrunners. Three were African American, two were Asian-American, one was Samoan-American and also a Hindu. And then there’s age, this group spans 41 years, the youngest is Buttigieg, 37 and the oldest is Sanders, who just turned 78.

Despite the age range, frontrunner status is now clustered among the septuagenarians. After Sanders comes former Vice President Joe Biden, who’s 76, then Elizabeth Warren, who is 70. With two older men, one young one and one woman, all of them white, it begs the question: what happened to this most diverse field of Democratic candidates?

The most common explanation is that Democratic voters are afraid to take any chance whatsoever in this most important chance to deny Trump another four years. Many point to Hillary Clinton’s failure to beat him in the electoral college (while she did in the popular vote) and that sexism among voters was indeed part of what took her down. So, many voters would prefer to play it safe and go with a more traditional looking candidate, like Joe Biden.

However, like all explanations for why anyone votes one way or another, there is no one answer. Dovetailing with this instinct among some voters to go traditional is one of the most interesting demographic phenomenon’s to come to light in the past year. White Democrats tend to form the very left end of the party, while people of color, especially black voters and Latinos on the more moderate to conservative end. While Buttigieg has been famously having trouble attracting black voters, Biden is by far their favorite, possibly because of the trust he built with them as Obama’s Vice President. Biden is also doing well with Latino voters. Democratic National Committee member Leopoldo Martinez is personally supporting Biden and is also co-chairing his campaign’s Latino Council. He told me that “Polls have Biden leading the Latino vote nationally, and specifically the Latino vote is giving him a solid lead in Texas and Nevada.”

The big question of whether Trump can be beat by a candidate from the populist left or from the moderate side of the party, most black and Latino voters lean moderate, siding with a candidate who happens to be an older white man. In keeping with the data that shows white Democrats leaning to the hard left, Sanders’ faithful followers are mostly white and there are the famously white male “Bernie Bros” from 2016 who took to harassing women  (including this writer) for choosing Hillary over him. Indeed, many analysists posit that if Biden and Sanders weren’t in the race, then their support would go to younger candidates. According to this argument, candidates such as Harris, Booker and Klobouchar might have a chance without Biden in the race. Warren might be consolidating a more commanding lead at this point if Sanders wasn’t around.

This leads us to an explanation heads into to realm of the uniquely American generational wars. In a country where we name our generations and squabble between them, there’s a fair amount of sentiment that the Baby Boomers are refusing to pass the torch. Their cohort has dominated the presidency since 1992 with Bill Clinton, George W. Bush and Donald Trump all sharing the same birth year, 1946. Despite his youth, Barrack Obama is also a Boomer. Members of perennially overshadowed Generation X wonder if their chances at the presidency (with candidates such as Senator Kamala Harris, Senator Corey Booker or Senator Amy Klobouchar) will be gobbled up by attention-seeking Millennials trying to jump ahead of the line (like Buttigieg and Congresswoman Tulsi Gabbard). And both Biden and Sanders aren’t even Baby Boomers, they’re the youngest end of the Silent Generation that came before.

Racial, generational and gender diversity is important across all levels of government because a democratic government should be representative of its people. While the race, age and gender of any given candidate is highly symbolic, alone it doesn’t necessarily win elections. They must also have the appeal and ability to win the necessary support to build a winning coalition within the party.

It is indeed difficult if not impossible to mandate any sort of diversity in a presidential system, but there is a minimum age requirement to be the U.S. president, it’s 35 years old. The average age for U.S. presidents at their swearing in is 55 and Trump was the oldest at 70. (My very quick and dirty calculation found that Spanish presidents have been on average much younger at about 47. ) Recently, former president Jimmy Carter, who is a very spry 94, expressed his concern about a president’s age. “I hope there’s an age limit. If I were just 80 years old, if I was 15 years younger, I don’t believe I could undertake the duties I experienced when I was president.” Of course, everyone ages differently and we do have a 78-year-old woman, House Speaker Nancy Pelosi, wielding enormous amounts of power with enormous amounts of energy, much to the relief of many in the U.S. and around the world. Women do tend to live longer and there is some evidence that women’s brains age a little more slowly than men.

Trump squeezed all he could out of the incident when Hillary Clinton wasn’t feeling well during a commemoration of 9/11, left the event early and was caught on camera appearing to faint as she approached her car. Trump mocked and imitated her, suggesting she was too old (she’s two years younger than him) and lacking in stamina to be president. Trump had already been tweeting that she should release her medical records before the incident, which she duly did. Trump’s own ‘release of medical’ records consisted of a letter from his gastroenterologist, written in Trump’s own bombastic style.

So, we know that Trump will drag this line out against any candidate—male or female—who is older or close to his own age. The seemingly endless primaries (voting doesn’t start until the Iowa Caucus on February 3) and debates has the upside of giving voters a chance to get to see candidates in a lot of different settings, not to mention, seriously test their grit and physical ability to withstand such a grueling process. In effect, no age limit is really necessary because someone who’s too old for the rigors of the White House won’t make it through to the nomination process.

By this standard, Joe Biden hasn’t been faring all that well. In the last Democratic debate, he got into very passionate discussion about education and the well-documented deficit of words that poorer children hear compared to wealthier ones. He made a plea for parents to leave the “record player on at night.” Now, this comment would have stood out if he said CD player or tape cassette, but record players are only remembered by hipster lovers of vinyl and people over the age of 50. Perhaps odder, is that this was in response to a question about slavery as America’s original sin. The record player comment immediately went viral on the social networks, was mocked by comedians and condemned by pundits as an unrecoverable error.

Slate published a piece where people over 60 expressed their concern over his age. To be sure, Biden is notoriously gaffe-prone, but he has also had a few moments of seeming tired or confused in debates and at the very limited events he does on the campaign trail. And he’s not alone. Bernie Sanders actually had a heart attack on the campaign trail in October and spent three days in the hospital. Like any smart campaign, they played down its importance, but a heart attack is no laughing matter at any age, especially 78.

This entire discussion is fraught with politically incorrect racism, ageism and perhaps a little sexism, the kind of thing that makes most Democrats cringe. But then again, it’s been their promise, even their brand, to be the party of diversity in order to represent all Americans and not just the white men who have been privileged since the country’s founding.

This article was originally published in the Spanish foreign policy publication esglobal.