My downstairs toilet seams to have no flushing power and doesn't fully drain.

Many causes for this so lets start with a basic question. Lift the tank lid and tell me where the water line is in comparison to the top of the white overflow tube.

At the max fill line, I adjusted it earlier it was inch below.

Ok good, now flush the tiolet and see if at least 75% of the tank drains before the flapper closes.

NO but even if you hold the handle down it doesn't help. The collar that flap sets on, sits higher than any that I have ever seen before. It sits two inches up, leaving two inches of water in the tank when it flushes.

Has this always been like this, when did the poor flushing start

I just bought the house, I know it's a newer toilet within a year of being installed.

So was it flushing poorly for you from day one?

Yes

Please explain the poor flush. Does the level raise, swirl around and slowly drain down without taking any solids. Or is it a week flush? More details please.

The collar that flap sets on, sits higher than any that I have ever seen before. It sits two inches up, leaving two inches of water in the tank when it flushes. That "collar" is the seat of the flush valve and will set off the bottom of the tank.
There are several things I would check:
1. Check the small jet hole in the bowl tom be sure it's not blocked with mineral build up. **and**
2. Some times when replacing a toilet the wax seal spreads instead of out. The restricts the flow and blocks the siphon action. Pull the toilet and if the wax seal is pushed in the flange bevel it out so it will spread out. Good luck and let us know how you make out. n Tom

The level raises, no swirl, drains really slowly and does not take solids. Already checked the jet hole. Pulling toilet I guess will be the next step.