In 2013 the democratically elected House of Commons passed Bill C-377 which would have weakened labour unions. That bill was stopped by the appointed Senate.
Today the democratically elected House of Commons is preparing to pass Bill C-23 The Fair Elections Act which seeks to undermine democracy. The appointed Senate is simultaneously preparing to stop it.
In all of these cases the majority in the House of Commons also had the majority in the Senate, but still the Senate stood up against the democratically elected Lower House. Despite being unpopular, especially in protecting abortion at the time, the Senate protected fundamental principles.
Democracy depends on womens' rights, labour rights, and actual fair elections to function; all things this Senate has saved.
Protecting democracy means protecting its principles; but principles aren't elected, and their application isn't always popular. Because of the obvious similarities with the Upper Chamber, for democracy's defense, an appointed Senate sounds perfect for the job.