Ambitious proposals for tackling climate change and transforming the economy are setting up one of the party’s most crucial debates heading into 2020.

Democrats are rallying to turn the “Green New Deal” into a centerpiece of their Capitol Hill agenda and the party’s 2020 platform — as soon as they decide what exactly it is.

The term has become a potent brand name for a slate of ideas for transforming the economy and fighting climate change, championed by progressives like Rep. Alexandria Ocasio-Cortez (D-N.Y.) and embraced, at least cautiously, by potential presidential nominees including Sen. Elizabeth Warren (D-Mass.), Sen. Bernie Sanders (I-Vt.) and Beto O’Rourke.

But not all Democrats have signed onto the full agenda that Ocasio-Cortez and her activist allies have rolled into their Green New Deal platforms — which encompasses proposals such as a complete switch to clean energy by 2030, big tax increases on the wealthy, retrofits of every building in the U.S. and a federal guarantee of a well-paying job to everyone who wants one.