The beating heart of the effort to resist President Donald Trump will descend on Atlanta on Thursday with a four-day conference of the nation's leading liberal activists and politicians.

The mission of the Netroots Nation event is to energize a legion of new activists ahead of next year's midterms, derail Trump's agenda and lay the groundwork to oust him in 2020. And they'll have backup from U.S. Sen. Elizabeth Warren and former Vice President Al Gore, as well as Georgia's two Democratic candidates for governor, Stacey Abrams and Stacey Evans.

Part pep rally and part insurgency training, the conference includes nearly 200 panels and training sessions designed to teach progressive activists how to reclaim state legislatures, advance LGBT rights in the South and master social media strategy.

Others aim to encourage liberals to run for office, whether they challenge incumbent Republicans or establishment Democrats. One even advises activists on how — and why — they should take over their local Democratic Party to bring a more liberal bent.

Read the rest of the story on MyAJC: Why thousands of liberal activists are headed to Atlanta for Netroots