Mistakenly assuming that the popularity of a theory is in some way indicative of a theory's correctness or accuracy is the definition of the fallacy.

ad populum (bandwagon Fallacy)

Explanation:

In an argument the use of faulty reasoning or something invalid to make a case is called a fallacy.

The statement here describes the ad populum or bandwagon fallacy.

The belief of the common masses in argument is used to make a statement. If the masses believe in something then that fact must be true even if the thing they believe in is factually wrong, is the definition of the bandwagon fallacy.

answer; if congress didn't act on certain requests;