A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

Black Republic, the • Black Republicans
Black Republic, the —Haiti (a West Indian State): My subject
is Haiti, the Black Republic; the only self-made Black Re-
public in the world.
Note: 
The expression does not correlate in meaning with the
phrase Black Country, the—(UK) a highly industrialized region
of west-central England centered on Birmingham: It is believed
that the Black Country got its name because of pollution from
these heavy industries that covered the area in black soot.
Black Republicans —(U.S. hist.) Republican opponents of
slavery, during the period which preceded the American Civil
War: The Whig party adopted the name of Republicans, and
were called by their opponents Black Republicans, from their
anti-slavery tendencies.
black sheep • black swan
black sheep —smb. who is very different from the other peo-
ple in the group and is considered a bad character: Every priv-
ileged class tries at first to whitewash its black sheep.
black swan —(also: white crow) said of a person or thing that
is extremely rare: After all, he may not be such a black swan
as Aunt Susan makes him out.
blank check • blank sheet
blank check —freedom to choose whatever course of action
one thinks is necessary: The coach was given a blank check by
the university to try and improve the team.
blank sheet—(also: clean sheet) 
1
. a fresh start when people
decide to forget about previous mistakes, failures, etc.: Man-
agers should start with a blank sheet regardless of the com-
mitments already made and resources applied. 2. said of the
human mind at birth, regarded as having no innate concep-
tions: Nor were they alone in their belief that a new-born’s
mind is a blank sheet on which society can write what it
pleased.