The previous few issues of the Screen Cartoonists Guild newsletter having been devoted to civics reading set the groundwork for their "Primary Election" issue.
As is the case in primary documents like this, the unsaid speaks as loudly as the said. I assume the California primaries in 1944 run the same as primaries today -they're "closed" (meaning you only vote for a candidate in the party in which you are registered). All of the endorsed national candidates went on to win their Democratic primaries -one unseating an incumbent. All but one, Archibald Young, won in the general election.
This, of course, would be the last election Franklin Roosevelt would participate in.