Some states now require supermajorities in their legislatures to approve tax increases. Others cannot raise taxes unless voters approve. Altogether, nearly 30 states have adopted some kind of limit on either spending or taxes.

Only Washington state requires both supermajorities and voter approval for a tax increase, and observers say that has worked well.

• A 1993 citizens' initiative limited annual increases in general fund spending to the percentage of Washington state's population change plus inflation increases.

• Also, tax hikes require a two-thirds vote in each house of the state legislature -- with voter approval needed if a tax increase results in spending over the limit.

• General fund spending -- which had been rising as much as 24 percent before these restrictions -- has been growing only 7 percent to 8 percent in each of the state's last three two-year spending periods.

Colorado has also been active in capping excessive state spending.

• That state set a 7 percent annual limit on spending growth in 1977 -- following up in 1991 with a 6 percent cap on annual spending increases.

• The following year, voters approved a formula capping spending increases at the rate of inflation plus population growth, or at 6 percent, whichever is lower.

• Moreover, voters must approve any tax increases, and any funds collected over the spending limit must be returned to taxpayers.

Tax policy specialists hope federal politicians and officials are watching these commendable efforts at self-restraint -- and will one day decide to emulate them.