I converted my traditional IRA to a Roth IRA in 2017. Can I undo it now?

A taxpayer who converted an IRA funded by deductible contributions to a Roth IRA in 2017 has until October 15, 2018, to undo it. This means recharacterizing the new account as a traditional IRA. However, conversions in 2018 and beyond cannot be undone. The Tax Cuts and Jobs Act of 2017 ended this opportunity.