Answer:
Due to the weakness of Federalists leadership
Step-by-step explanation:
In 1820 Monroe's re-election campaign went unopposed because the Federalists had become extremely weak at the national level and no Democratic-Republican challenged Monroe which made Monroe the only presidential candidate. So with the weakness of Federalists powers and representations, after 1824, the Democratic-Republican Party broke between supporters of Andrew Jackson and supporters of Adams and both candidates condemned the caucus system. Therefore from 1831 onward, the Congressional nominating caucus was replaced with national presidential nominating conventions.