Why the Republican Party and the Democratic Party are so different?

In a few days, incumbent President Donald Trump of the Republican party and former Vice President Joe Biden of the Democratic party will face off in what is shaping up to be a highly unusual election.

The Democratic nominee, Joseph R. Biden is a veteran politician who served decades as a Senator from Delaware, holding prominent positions such as the chair of the Senate Judiciary Committee and the Senate Foreign Affairs Committee before serving as Vice President for 8 years under Barrack Obama.

Mr. Biden represents the centrist wing of the Democratic Party. He defeated rivals who were supported by a younger, more progressive wing of the party such as Senator Bernie Sanders and Senator Elizabeth Warren in the Democratic Primaries to become the nominee of the party.

Donald J. Trump is a political anomaly in America. Before becoming President, he had never held any public office but was a well-known real estate developer and a reality TV star hosting his own show “The Celebrity Apprentice” for many years.

Mr. Trump’s nationalist message is hugely popular in the Republican party, receiving the support of over 90% of voters who support the Republican party, a figure much higher than the previous Republican President George W. Bush.

He has constantly bashed the media, American allies, the democrats, the “blue states,” his critics, and some government officials including his former staffers. He has called for arrests of his political enemies and floated debunked conspiracy theories and joked that he should be allowed to serve more than two terms, a clear violation of the U.S. Constitution.

Why the two major parties in America chose such different figures? The key to understanding this, I believe, is to look at the base of the parties.

In the 2016 election, Donald Trump led among men by 11% and lost among women by 13%. He had a 20 point lead among white voters and lost all other racial groups by much wider margins ranging from 38% to 81%.

This is reflected in party affiliation. In general, white, male voters are likely to support the Republican party while women and other racial and ethnic groups are likely to support the Democratic party. In other words, the Republican base is much more monolith than the Democratic party.

This creates an opening for outsiders like Mr. Trump to exploit. Donald Trump had not strongly supported the Republican party until 2012, but he announced his candidacy in 2015 and became the nominee a year later. He did so by convincing white men that he was the right person for the job. Because the Republican party base is a monolith, he only needed to convince one group of voters in order to become the nominee.

This is a stark contrast to the Democratic party. Senator Bernie Sanders, who has an enthusiastic following from young, progressive voters lost the contest for nomination because he failed to convince more moderate voters and black voters in the South that he could win. Those voters coalesced behind Biden which ultimately led to his victory.

In fact, Mr. Sanders won, depending on how you count Iowa, first 3 contests while Biden finished 4th in Iowa, 5th in New Hampshire, and 2nd in Nevada before winning by an overwhelming margin in South Carolina, a state with a large black community.

This shows the structural difference between the two parties. In order to win in the Democratic party, you need to appeal to multiple different groups that, in some cases, have different interests. But you can become the nominee of the Republican party by just appealing to one group of voters.

For example, young, white voters tend to be more progressive than others while older black voters are more moderate. Highly educated female voters were likely to back Warren while moderate white moderates backed Biden. The co-existence of these different groups makes the Democratic party much harder for an outsider to sweep in.

The problem for the Republican party is that it is not easy to re-make the party structure. Appealing to racial and ethnic minorities will inevitably cause a backlash from the anti-immigration base, which the party cannot afford. The Republican party, however, has a structural advantage in that, the Electoral College and the Senate heavily favors certain less urbanized states that are overwhelmingly white. Unless the system in which the American voters are represented is reformed, the Republicans might be able to hold onto power.