Madam Secretary Season 5 Episode 20 revolves around Elizabeth's decision to run for President.

Elizabeth announces her resignation but wants to assist on getting the climate migrant treaty through the Senate. Dalton lets her, against Russell's advice. She is able to deal with Callister's xenophobic concerns, but falters when a Progressive senator questions her about fossil fuel.

Elizabeth convinces the naysayer to sign on to the treaty and sends Peter to Geneva for the UN conference. All seems to be going well, but then all the members of the conference are poisoned and there are no survivors. It turns out this is a terrorist attack by a White Nationalist group. To make matters worse, many of the other countries are now pulling out of the accord because Callister is threatening to pull the US out if he is elected.

Elizabeth speaks to the Russian delegate, who hints that Callister has ties to Russia. She learns from Dalton that Callister's campaign manager has been arrested for treason and that Callister is under investigation. Callister drops out of the race, but Elizabeth isn't sure she wants to stay in. She thinks she's needed as Secretary of State.

Meanwhile, the staff is asked to vet Elizabeth's kids for potential problems, which leads to an awkward moment between Blake and Stevie.

To find out what happens, watch Madam Secretary Season 5 Episode 20 online.