Think of the state budget like the cost to paint your bedroom. Last year the painter wanted $75 but this year, inflation you know, he says the price is $80. So you approve the price and the painter paints away. When it is time to pay you do not have four $20 bills so you give him a $100 bill and expect $20 in change.
Those who do not like the kicker would say: “Whoa, you have $100 so I will just keep the extra $20 for the new compressor I need.” Well, the kicker says “no” and since $80 was all that was planned to be spent the $20 must be “kicked back.”
The people put it in the Oregon Constitution that we get the “change” whenever tax collections etc. are greater than 2% higher than planned spending.
It is not just the $20 that is important but, the future spending that would result. In the next biennium the legislature would tend to look for an inflationary increase above the $100 instead of $80. So as the years pass the budget would grow at a rate much higher than inflation which it did in the pre-kicker days.