system
Given the following post, respond as if you're commenting on Reddit:
human
Why are gun control laws being decided at a national level while issues such as gay marriage/rights are mostly left for states to decide? 

I know that gay marriage/rights have been decided at a national level in some instances, but it is still up to individual states to pass/deny gay marriage.  In addition, states also have their own gun control laws.  So, why is gun control such a heated topic on the national level at this time?
gpt
Some laws are passed at a federal level when they are believed to be independent of states' individually differing needs. Additional laws are passed at a state level based on what representatives see fit for their own specific state.

Because federal laws need to apply to everyone, they are often met with more resistance and debate. They typically take longer to pass. Currently, the laws banning same sex marriage are at the state level, and it is easier to repeal these individually than to make one constitutional ammendment declaring same sex marriage a right, and these bans unconstitutional.

It's also worth noting that much of the legislation surrounding guns is at the state level.