measure the drapes

Etymology
After the election of a new President of the United States, the decor of the White House is changed to reflect the taste of the new administration. Historically the task has been left to the First Lady, the wife of the President. During the 1940 campaign for President, Senator Robert Taft of Ohio sought the Republican Party nomination. His wife, Martha Taft, gave an interview to the Evening Independent of St. Petersburg, Florida, in which she expressed certainty of his victory:



Since Taft won neither the general election nor his party's nomination, the idea of "measuring the drapes" for installation in the White House became a metaphor for premature preparation for victory, or over-confidence.

Verb

 * 1)  To make premature or unwarranted preparations for victory, especially election to public office.