As discussed in the Washington Post article, the Heritage Foundation is a conservative policy institute $($or "think tank"$)$ that, among other work, maintains a database of election fraud cases. The database records cases of electoral fraud in which there has been a prosecution or other official action that resulted in a finding of wrongdoing. However, a representative of the Heritage Foundation interviewed for this article claims that actual fraud may be higher. Why is this?

not all allegations of election fraud are founded in fact

the database contains only a random sample of prosecutions, not all prosecutions

there are many more allegations of election fraud that are never recorded

not all instances of voter fraud result in prosecution