The turmoil cast a pall over

[dilermando]

From Chancellor's grave warning sends pound plunging, pushes up holiday prices and kills off hope of interest rate cut | Mail Online

In the text below, what does "cast a pall" mean?

The turmoil cast a pall over what is supposed to be the first leg of Gordon Brown's political relaunch today, with the announcement of a £1billion programme to help the housing market.

[buggles]

A pall usually refers to smoke - "A pall of smoke rose high into the air over the forest fire".
In this context, the pall was cast over the relaunch like a dark cloud making it far less attractive than what was intended.

[BobK]

I believe the metaphor ('pall of smoke') is based on the piece of material used to cover a dead body. When you 'cast a pall' over something you make what was meant to be happy sombre, if not sad.

b

PS: http://www.etymonline.com/index.php?term=pall - not a dead body (directly) but a coffin.