Taxation without inflation

While I have my fingers crossed that this bill will pass, I don't have my hopes up that it will. Still, it would be a huge benefit to anyone with a capital gain:

The old fight over indexing the basis for the capital gains tax is starting up again, and this is shaping up to be the best chance ever to finally end the unfair tax on inflationary gains. Legislation sponsored by Reps. Mike Pence of Indiana and Eric Cantor of Virginia, H.R. 6057, would use the Gross Domestic Product implicit price deflator to index the capital gains tax basis for inflation, ending one of the most egregious practices of our tax system.

The authors go on to mention that it would be possible to implement this simply by having the Treasury Department interpret that the "cost" basis of an asset include inflation. I see that happening even less, unfortunately.

Looking around at different charts, since 1982 the CPI is up 104% (I couldn't find the same number for the GDP deflator) due to inflation, while the S&P500 is up about 1800%. Not a huge benefit to be able to adjust for inflation. But imagine buying stock at the top of the market in 2000/2001 and selling now. Most market indices are slightly up, but inflation will more than wipe out most of those gains.