It has been before the Supreme Court who upheld it, as they should (for example United States v. Ursery, 116 S.Ct. 2135 (1996)). Civil asset forfeiture was enacted by the first Congress in a number of statutes, again for example Act of July 31, 1789, Sections 12, 36; 1 Stat. 39, 47. Since the first Congress enacted and sent the Bill of Rights to the states for ratification, they had a pretty good idea whether forfeiture violated it. So while I think using it is a terrible idea, it isn't an unconditional one.

That is certainly not where asset forfeiture came from. It existed prior to the US and the very first Congress passed a number of civil forfeiture laws.

The very first Congress passed civil asset forfeiture laws (Act of July 31, 1789, Sections 12, 36; 1 Stat. 39, 47 among others). That Congress was mostly made up of people who had either attended the Constitutional convention or were leaders in pushing for the adoption of the Constitution. You're basically arguing that you have a better idea of what is Constitutional than they did. Hard argument to swallow. I'm not saying these examples are a good use of the law, they are not. But they are simply a bad idea and not some violation of the Constitution.

Article 1, Section 4: The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Place of Choosing Senators. Congress has the power to actually make and alter State Law for elections (at least those where Congressional members are standing).

A large number of people have mentioned that the Federal government would need a treaty to supersede state law on elections. Not sure why nobody seems to actually read the Constitution, but it gives Congress more power over State election laws (at least those where Congress-critters are being elected) than it does over any other subject, bar none. Article 1, Section 4: The Times, Places and Manner of holding Elections for Senators and Representatives, shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Place of Choosing Senators. As the above text states, Congress can actually MAKE state law in this area.