The Morning Rundown: Argument over rules delays start of Senate trial

Good morning, NBC News readers. An "impasse" over the Senate trial of President Donald Trump, Democratic candidates clash on stage, and a missing Texas newborn has been found alive according to her family.Here's what we're watching.

Feud over rules of engagement leads to 'impasse' on Trump's Senate trial

After impeachment, a pause. The country may have to wait for a Senate trial of President Donald Trump as Democrats and Republicans continue to argue over what the rules of the trial should be.

Senate Majority Leader Mitch McConnell, R-Ky, said Thursday that he has reached an "impasse" with Senate Minority Leader Chuck Schumer, D-N.Y. The pair have openly feuded over how the trial should be handled following Trump's historic impeachment Wednesday.

House Democrats say they may not submit the articles of impeachment to the Senate unless McConnell agrees to rules that ensure a fair trial, which Schumer has said should include witnesses who did not give testimony to the House. All this could mean Trump will have to wait indefinitely to likely be acquitted by the Republican-controlled Senate.

Video: McConnell: 'Fine with me' if Democrats never send impeachment to the Senate.

Democratic candidates clash on stage with less than two months until voters weigh in

The seven Democratic presidential contenders left in the race clashed in a lively debate in Los Angeles Thursday night, with each making the case for why they are best placed to take on President Donald Trump in 2020.

The less crowded format meant there was more room for some head-to-head conflict between the contenders. Frontrunner Joe Biden escaped largely unscathed without that many attacks, but he still found time for a heated exchange with Bernie Sanders, I-Vt., over Medicare funding.

NBC News' Shannon Pettypiece has a roundup of the winners and losers here.

Meanwhile, Former White House Press Secretary Sarah Sanders apologized for mocking Biden for stuttering while giving an answer during the debate. Biden tweeted that he has worked to overcome a lifelong stutter. "It's called empathy. Look it up," he added.

Video: Watch the Democratic debate in less than 5 minutes

Missing Texas mom found dead but newborn baby found alive in "good condition"

A body believed to be that of a missing Texas mother was found Thursday night near Houston, while her newborn has been discovered alive, a family member told NBC News.

What is likely to be the body of Heidi Broussard, who has been missing for a week, was found in Jersey Village, Texas, police told her mother, Tammy Broussard.

Medicare expansion has come to Idaho — but welcome changes are mired in uncertainty

For Melissa Turner, proposed changes to Medicare rules will be a big deal. She lost her job and health insurance and has tens of thousands of dollars of medical debt.

She is one of about 91,000 who would benefit from a higher income threshold from Jan. 1., meaning she is less likely to increase her debt.

But there's an ongoing battle in the state's Republican-controlled legislature over waivers that could limit the scope of insurance expansion — despite 62 percent of the voters backing the scheme at the ballot box last year.