Agreed, the statements that Politifact chooses to cover are contentious and have high visibility. In the specific set of data points that were used to evaluate Politifact, a larger percentage of the statements made by Republicans are classified lies and more harshly (see article below from 2011). This proves nothing about the overall number of lies made by individuals within the Republican and Democrat parties. There are numerous ways this sort of situation within Politifact can come about even after excluding bias from Politifact. For example, a unique time period in which a small number of individuals who identify as Republicans are independently making more outrageous claims which skews the result. Or a time period in which a specific talking point (generally proven false) is being pushed as a narrative by a portion of a party but not a majority of the party (e.g., the 2020 election was stolen, or Donald Trump colluded with Russia during the 2016 elections).
Point being, reaching the conclusion that Republicans lie more via Politifact or the findings of the original study is a fallacy. And reaching the conclusion that Politifact is biased is also a fallacy.
The original article here: https://archive.ph/Drhw