So we know that words are powerful, and evocative, and resonant. Emily Dickinson knew exactly what she was doing when talked about "Cavalries - of love".

So why did Tony Blair think it a good idea to say the Black Watch would be home by Christmas in 2004?

And why certain Republicans still bandy around the term "Un-American"?

Do they not know the associations they are evoking? Or maybe, in the case of the Republicans, they don't care.