Republican leaders billed their decision to abandon a controversial plan to tax companies' domestic sales and imports as an essential step toward uniting their efforts to overhaul the U.S. tax code—but its death adds new complications to an already intricate task.

Though the so-called border-adjusted tax had circled the drain for months, its last gasp on Thursday greatly increased the chances that any tax cuts Congress delivers will be shallower than President Donald Trump and other GOP leaders want, or shorter-lived, experts said. Without the proposal's estimated $1 trillion in new revenue, a resulting bill may look more like the temporary tax cuts of 2001 than the once-in-a-generation overhaul of 1986 on which Trump and lawmakers have set their sights.

The death of the BAT “means a lot,” said Douglas Holtz-Eakin, who leads the GOP-aligned research and advocacy group American Action Forum. “Obviously it was a big pay-for so it puts pressure on the other pay-fors. There's a lot at stake.”