Gov. Jay Inslee of Washington is running a campaign almost singularly focused on combating climate change. It is his signature issue.

The context

• Mr. Inslee often points to his leadership on climate change as a state executive to argue that he is best equipped to tackle the existential threat.

• He co-founded the United States Climate Alliance, a bipartisan coalition of governors dedicated to reducing greenhouse gas emissions, and has passed clean energy legislation through his statehouse.

• As a presidential candidate, he has rolled out a multipronged plan to battle climate change that includes a call to eliminate planet-warming emissions from power plants, vehicles and buildings over 10 years.

How he uses it

• Mr. Inslee is betting that his attention to climate change can distinguish him in a sprawling Democratic primary field.

• He has repeatedly implored the Democratic National Committee to hold a debate that is focused exclusively on climate change. (The D.N.C. has refused.)

Obstacles

• Previous attempts to pass significant climate change legislation have largely failed, as global warming has devolved into a partisan issue. Republicans recently seized on the Green New Deal, portraying the resolution as absurd.

• The Trump administration has rolled back environmental regulations and is actively seeking to undermine the science on which climate change policy rests.

• Most of the other candidates for the 2020 Democratic nomination have ideas about climate change, too.