"Down in my boots"

Question

May Sarton, an early 20th century poet, wrote in a letter:

"Politically I am down in my boots."

What could she mean? Angry? Frustrated? Disheartened?

Answer 1

To be phrase "down in [one's] boots" seems to have meant, at one time, "to have lost courage" or "to have felt [one's] spirits sink." Joaquin Miller, The Danites in the Sierras (1881) cites it and kindred expressions as indicating a lack of popular esteem:

"Hasn't got the soul of a chicken!" "Caved in at last!" Gone down in his boots!" "Busted in the snapper!" "Lost his grip!" "Don't dare show his hand!" These and like expressions, thrown out now and then from the little knots of men here and there, were the certain indications that Sandy had lost his place in the hearts of the leading men of the Forks.

And Walter Besant, The Chaplain of the Fleet (1881) has this:

'God bless my soul!' cried the merchant, changing colour so that I for one felt quite certain that his [money] was there too, and that his courage was down in his boots as well, to keep the money company. 'Bless my soul! hanging, mere hanging, is too good for such villains.'

Also common is this wording, from Gilbert Heron, "The Despatches for Gibralter," in The Harmsworth Monthly Pictorial Magazine, volume 1 (1899):

"Oh! The blackguards!" I yelled despairingly, my heart down in my boots again, for the cruiser was now rapidly nearing us.

There was, unfortunately, no chance of our torpedoing her, for our stern-tube had been knocked to atoms by the shell which had come in astern.

The wording was sufficiently common in 1869 that an adviser on proper speaking took the trouble to denounce it. From Robert Philp, "Correct Speaking, Hints on Writing" in Enquire Within upon Everything; to which is added Enquire Within upon Fancy Needlework, 37th edition (1869):

Avoid such phrases as "No great shakes," " Nothing to boast of," "Down in my boots," "Suffering from the blues." All such sentences indicate vulgarity.

Answer 2

It seems (I only find it in this Chinese resource!) it's a regionalism meaning:

/ be frightened out cf one's wits/go down in one's boots/frightened out of one's senses/