An article today discusses the difference between the U.S. and Canadian political systems and claims to answer a simple question, but the main issue remains unanswered.
Why can Canada’s parliament vote for a change (in gun laws), but, even when a single party controls both the U.S. House and Senate, a change (in gun ownership laws) is all but impossible?
Is this, for example, one of the cases when the bar for a Senate vote is not simply 50% + 1 (VP, in the current Senate), but 60% or even two-thirds (66 or 67?)?
If two members of the House of Representatives sponsor a law (such as a background-checks law), the vote passes the House (assuming unanimous vote among representatives from the Democratic Party), and the vote is ratified by 50 Senators + VP vote (for the current Senate split at 50-50), does that not suffice for the law to pass (barring a presidential veto, which wouldn't be a concern here)?
If the answer can be summarized as "If a few US Senators are opposed to a legislation then they can discuss it endlessly (filibuster)," please write that simply and explicitly. But why then does it matter whether 51 Senators or 80 Senators approve a bill, if in either case the remaining 49 or 20 Senators could filibuster it? How does endless debate suddenly become not viable as a tool for political paralysis if only 20 Senators disapprove?
The intended stress in the question is not "why does the Canadian system work?". It works by a simple majority. The question instead seeks to understand how the U.S. system can be bogged down by procedures even when both branches of Congress have majorities that pursue an objective (whatever that objective might be; today it's no guns; tomorrow it may be no abortions).