What more likely raising the USA drink age 22 or lowing it to 20?

Raising it would be more likely than lowering it. You see the drinking age is what it is due to drunk driving accidents, not that folks under 21 were causing more accidents than folks over 21, but that it was a soft target.

The other thing that happens is citizens of a state will complain to the local legislature about the high cost of car insurance. The insurance industry then turns around and tells the states if you want lower overall insurance rates than you need to raise the minimum drinking age. Since 18-20 year olds don't pay attention to politics the drinking age gets increased.

Neither. Why would anyone go through all that time, effort and expense to change the drinking age by one year?

i think 21 is fine as it is.

However, i don't see any difference between tobacco and alcohol so I think they should be both the same age be it 18 or 21.

I think 21 is better as people generally mature a bit during college.

I don't think there is any big incentive or a push to change it in either direction.

I suspect that some northern states that border Manitoba, Ontario, and Quebec would like to lower the legal drinking age to 18 or 19 to match what's just across the border in Canada. But since the federal government supplies funds for infrastructure based on the drinking age being 21 or higher, there's no way those states would want to give up the right to obtain those funds.

Neither.

The drinking age is established by each state. For the state to be eligible for the funds for interstates/highways the state must have a drinking age of 21 or more.

= When the age was increased from 18 to 21 in the 1970s and 1980s, it GREATLY decreased the amount of drunk driver fatalities.

Why would the age be increased to 22. In the USA, there is no magic number with 22.

More likely it would go in my opinion, but the chances of that ever happen I think are extremely low at best.

yeah... I was surprised to find out the drinking age was 21 when in the UK it is 18

but probably not really likely to be either

i think both are very unlikely.