Trump impeachment: Senator Collins working to allow witnesses at trial – as it happened

Kari Paul here, logging off for the weekend! Here is a summary of the key events of the last few hours:

• In a court filing on Friday, the Trump administration said it does not want the Supreme Court to hear its appeal of the Affordable Care Act any time soon, to give lower courts time to make rulings on it.
• Bernie Sanders is leading the latest polls in Iowa, with 20% of the vote. Warren follows close behind at 17%.
• Alexandria Ocasio-Cortez defended her decision on Friday not to pay dues to the Democratic Congressional Campaign Committee (DCCC).
• Two parents who were separated from their children as a result of zero-tolerance immigration policies have filed a lawsuit against the Trump administration alleging child abuse over family separations.