PV International Desk : Joe Biden faces scrutiny over Ukraine, Elizabeth Warren is surging and Bernie Sanders had a heart attack, but recent developments in the Democratic presidential battle are getting minimal attention, swamped by Washington’s impeachment obsession.

Most Democratic candidates are pounding the pavement in early voting states like Iowa, but they are finding little oxygen for the nomination race.

Broadcast and cable news have been dominated by a burgeoning Ukraine scandal that has engulfed the White House and prompted House Democrats to launch an impeachment investigation of possible abuse of power by Trump.

The drama threatens to overshadow what could be a pivotal moment in the Democratic nomination race: Tuesday’s three-hour debate with the party’s top 12 candidates.