There is a new proposal in the Harvard Law Review titled: "Pack the Union: A Proposal to Admit New States for the Purpose of Amending the Constitution to Ensure Equal Representation".
Lamenting the results of the last election, the article suggests subdividing the 91% Democrat leaning District of Columbia into 127 new states will give them the power to amend the Constitution at will without worrying about the opinions of the rest of the country:
To create a system where every vote counts equally, the Constitution must be amended. To do this, Congress should pass legislation reducing the size of Washington, D.C., to an area encompassing only a few core federal buildings and then admit the rest of the District’s 127 neighborhoods as states. These states — which could be added with a simple congressional majority — would add enough votes in Congress to ratify four amendments: (1) a transfer of the Senate’s power to a body that represents citizens equally; (2) an expansion of the House so that all citizens are represented in equal-sized districts; (3) a replacement of the Electoral College with a popular vote; and (4) a modification of the Constitution’s amendment process that would ensure future amendments are ratified by states representing most Americans.
From my research, new states can be admitted with a simple majority vote of congress. They can't be carved out of existing states, but D.C. is not an existing state. Therefore my question is:
Would it be Constitutional for the party in power to add as many states as they wish (D.C or otherwise)? Are they any limitations on this? Would the other states be able to stop this?