The English idiom “in the running” refers to someone who is a candidate for something, or who is still participating in a competition. This general meaning gets used in specific ways to refer to eligibility. The phrase “in the running” is part of the category of “competition metaphors,” where many different idioms relate to either concrete or abstract forms of competition in common English.
Word historians date this phrase to the second half of the 19th century. Many believe that the term originated from horse racing, where horses that were still eligible to win the race were “in the running.” Over time, this phrase became abstracted to refer to any type of eligibility in a competition, whether referring to something physical, like a race, or some more nebulous challenge.
This idiomatic phrase is often used in modern English to refer to an individual. For example, someone who is a member of a company who is competing for a promotion within a department might be “in the running” for the better job, when being considered along with other colleagues. Similarly, someone who is involved in a lottery or raffle might be “in the running” to receive some prize.
In addition to talking about individuals, English speakers who use the above phrase might be referring to various business parties or organizations. For example, if a grant is to be given to only one of several municipalities, each of those single municipalities who has applied for it could be said to be “in the running” to receive the grant. The phrase doesn’t automatically indicate competitive effort between eligible parties, it’s just a way to talk about general eligibility.
The above phrase is one idiom that has its corollary opposite. English speakers also commonly refer to someone being “out of the running.” The use of this phrase would indicate that someone is not eligible or not participating in a certain competition. This is similar to other idioms, such as “out of commission,” which indicate that someone is indisposed. Both of the opposite phrases are commonly used in question form, as well as in affirmative or negative statements: for example, in, “he is in the running,” and, “he isn’t in the running,” as well as, “she is out of the running,” and, “she is not out of the running.”