The meme earns a smirk. BUT !
Is there a deeper story here?
In a general election, a partisan voter has incentive to vote for the candidate of his own party, even if ideologically he may prefer the opposing candidate.
Why?
In each house of the U.S. federal legislature the legislative agenda is powerfully influenced by the political party that dominates by %population. The majority rules. BUT !
In the primary?
In primary elections, candidates WITHIN the party compete against one another. Thus primary elections tend to be more concept based.