Explain me why some americans oppose the statehood of DC ?

repubs don't want more Democrats in Congress

It's politics, of course. DC statehood would add new legislators to Congress, which would probably vote Democrat; thus, the Republican Party would never allow it to happen. The same thing would happen in reverse if DC was majority-Republican.

Their system is quite ridiculous with having two senators per state regardless of population. Wyoming has 600,000 people; California has 40 million.

Statehood for DC would add 2 senators in a strongly Democratic area, so that’s the real reason that non-Democrats would oppose it.

The founders created DC so that the nations capital could not show favoritism to a particular state . The Libs want to make it a state to pack the house and senate with more libs . It goes against the intent of the framers of the constitution , as most libs usually do .

The greater metropolitan area of the city (which is about five million) is falls into other States for representative purposes. So the question is not quote correct.

However, there is an area within the city proper (The district of Columbia) with about half a million people which is 'stateless'. That is a contradiction and ironic given that it contains the houses of the US national government.

To give it full state idemtity, I think you would need a constitutiomal ammendment, which would need to pass through all branches of the US government and perhaps more besides (chip in if anyone knows more). Given that it is a city area and dominated by public sector workers, the new state would be heavily Democrat and the Republicans would fight hard to stop it from happening.

Puerto Rico is kind of similar.

The Constitution, which only takes 20 minutes to read, stipulates that the seat of federal government be in a "federal district," not a state.

Because DC votes Dem is why “some” people oppose statehood.

Easy.

DC was created as a home base for the federal government. As such, its inhabitants are either federal employees or in some way associated with the conduct of the federal government, and in many cases temporary residents. Awarding just that handful of federal employees with 2% representation in the US senate would be to award them with a disproportionate influence in the affairs of the government.

For those who complain about being deprived of representation, a better solutions would be to treat them like members of the Armed services with voting right in their home state or state of their choice. If lifelong residents of DC, with no "home state" they could also be made citizens of the state of Maryland.

Because DC already has representation in 2 states. They also already get electoral votes.

There are more people in the Denver Metro Area than in D.C., and several times more than that in the rest of the state. I suspect you are thinking of Wyoming.

Just reabsorb DC into Maryland if the concern is “lack of representation”. But that’s not the reason, of course, it’s politics. Democrats want the additional senators and electoral votes since DC would be a blue state.

As a Canadian we get a little less coverage on stuff like this. I am curious why this is suddenly coming up now. I mean I don't see it as a bad thing for the people of DC. I am just curious what the catalyst was for this.

Because the founders didn't want a state to have the capital in it to prevent preferential treatment

There are really two things at play here...

1. Fear of change
2. Fear of a power replacement