PolitiFact miscounts American deaths during WW2?

When a PolitiFact fact check's subject matter involves math, we (figuratively!) smell blood in the water.

This item came from the PolitiFact article "Joe Biden's inaguration in extraordinary times, fact-checked," published Jan. 20, 2021. Notably, PolitiFact has only done one Truth-O-Meter rating on claims from President Joe Biden since mid-December. That's assuming PolitiFact's page showing Biden's fact checks is accurate.

As it turned out, PolitiFact was right that Biden was "close to accurate." But PolitiFact made a significant methodological blunder in reaching its conclusion. The mistake appears right away in PolitiFact's explanation for its judgment:

As Biden was speaking, the Johns Hopkins University coronavirus tracker was reporting 402,269 deaths in the United States. That is just shy of the 405,399 U.S. deaths during World War II, according to the Congressional Research Service. With the seven-day moving average of coronavirus deaths reaching 3,015 on Inauguration Day, the four-year World War II total was due to be matched by the coronavirus either on Jan. 20 or 21, less than a year after the virus reached the United States.

PolitiFact reports incorrectly in the second sentence of the above paragraph. The Congressional Research Service source document does not give a total for all the American lives lost in World War II. It gives a total for the number of military personnel lost during the war (bold emphasis added):

This report provides U.S. war casualty statistics. It includes data tables containing the number of casualties among American military personnel who served in principal wars and combat operations from 1775 to the present. It also includes data on those wounded in action and information such as race and ethnicity, gender, branch of service, and cause of death. The tables are compiled from various Department of Defense (DOD) sources.

The total PolitiFact used omits more than 10,000 civilian casualties, including nearly 10,000 from the U.S. civilian merchant marine. We don't see where Biden limited his statement to military personnel.

PolitiFact went on to suggest Biden would be right by extrapolating the numbers forward for a full year since the U.S. started to log covid deaths. But doing that turns Biden's claim into a prediction. PolitiFact supposedly does not fact check predictions. Going on the facts alone, Biden was off by more than 10,000 deaths. PolitiFact made his error appear considerably smaller by using a flawed approach to its fact check.

It's what we call PolitiFact's "Rubberstamps for Democrats" program. We argue that the tendency to award lazy favorable ratings to Democrats (and not Republicans) counts as one evidence of PolitiFact's political bias.