• Dean Obeidallah, host on SiriusXM Insight 121, calls in at 9:30am ET / 6:30am PT to talk about why the GOP should apologize to Benghazi familes

• Charlie Pierce of Esquire’s Politics Blog calls in at 10:30am ET / 7:30am PT to talk about Citizens United and this presidential race

• Podcaster Jody Hamilton joins us in the Los Angeles Bureau at 11am ET / 8am PT for “Total Trollop Tuesday”

• The 2016 Democratic presidential candidates will take the debate stage for the first time tonight, at 8:30pm ET in Las Vegas, Nevada. Hosted by CNN and Facebook and sanctioned by the DNC, the debate will be held at the Wynn Las Vegas, and Anderson Cooper will moderate.

• On the eve of the first Democratic debate, Hillary Clinton showed up unannounced to a union protest in the shadow of Donald Trump’s Las Vegas building, telling the real estate mogul to “represent all of the people of the United States.”

• Sheldon Adelson, one of the GOP’S most sought-after contributors, is leaning increasingly toward supporting Marco Rubio — and the Florida senator is racing to win the backing of other uncommitted megadonors.

• If Rep. Paul Ryan doesn’t run for House speaker, it could cause a free-for-all as about a dozen members maybe considering jumping into the race.