In science and philosophy, itâ€™s called â€œOccamâ€™s Razor:â€ the problem-solving principle that the simplest explanation is usually the right one.
The rule applies to politics. It demonstrates why Democrats lost races for Congress and state legislatures even as President-elect Joe Biden won a sweeping victory.
The simplest explanation is that Biden was able to separate himself from a cluster of negative issues and images that cost other Democratic candidates. â€œDefund the policeâ€ was the most damaging.
Democrats might wonder how goals like â€œend police racism,â€ â€œstop unjustified killingsâ€ and even â€œreform the policeâ€ got so far out of whack.
Congressman James Clyburn, whose endorsement of Biden was the most decisive event in the presidential race, blamed â€œdefund the policeâ€ for Democrats losing a congressional race in South Carolina.
As we get distance from and gain perspective on the election, itâ€™s clear Donald Trump energized a â€œwhite waveâ€ of working-class voters that overwhelmed Democratsâ€™ hope of a â€œblue waveâ€ that would sweep Republicans from control of the U.S. Senate, House and state legislatures.
Race and religion played a part. As did fears that Democrats would raise taxes, take away health insurance, hurt small businesses and kill jobs â€“ the familiar â€œsocialistâ€ litany.
There were cultural, even personality, factors. Democrats, as one critic put it, can come across as â€œmoralistic snobs.â€
But nothing cut as deeply as the suspicion that Democrats excused crime, looting and rioting, as well as the fear they would handcuff the police and fail to protect innocent citizensâ€™ lives and property.
That suspicion and fear hurt Democrats in some Latino communities and helped Trump win some Black male votes.
How did Biden escape the damage? How did he win a 306-223 electoral vote victory, exactly the same as Trumpâ€™s victory in 2016?
First, Biden was a familiar figure. Heâ€™d been in Washington since 1972. Second, he had an image as a moderate; he even was criticized for it in the Democratic primaries, where he vanquished more liberal opponents. Third, he made clear where he stood in the fall campaign.
Biden told 60-70 million Americans who watched the debates that he wasnâ€™t for defunding the police. He promised he wouldnâ€™t raise taxes on people making under $400,000 a year. He promised he wouldnâ€™t take away private health insurance.
Trump undercut his own argument against Biden. In the second debate, he attacked Biden for passing a tough crime-fighting bill in the 1990s. Itâ€™s hard to paint your opponent as soft on crime when you attack him for being too hard on crime.
Other candidates didnâ€™t have Bidenâ€™s armor. One legislator in North Carolina told me Democratic candidates here had a hard time deflecting TV ads and mailers tying them to â€œdefund the police.â€
The slogan is a flash point now as Democrats debate the future of the party. As they say, â€œItâ€™s about who we are as a party.â€
Who are they? A Pew Research survey last January found that 47% of Democratic and Democratic-leaning registered voters describe themselves as liberal. More than half said they are moderates (38%) or conservatives (14%).
How about Black Democrats? In 2019, Pew said, 43% called themselves moderate, 29%, liberal and 25%, conservative. This year, Latino voters showed theyâ€™re not monolithically liberal or Democratic-leaning.
How about history? From John F. Kennedy in 1960 to Joe Biden this year, Democrats usually nominate moderates over liberals for President.
Given all that, as they look to 2022 and 2024, Democrats might ask how they got tagged with the most toxic political label of 2020.