Today's installment of campaign-related news items from across the country.
* Though Ted Cruz and Donald Trump are already scheduled to participate in a CNN forum this evening, Cruz has challenged the Republican frontrunner to turn the event into a debate. As things stand, there are no additional GOP debates scheduled.
* The latest Gallup polling shows Donald Trump's Republican supporters far more enthusiastic than his Republican rivals' supporters. And though this cuts against the conventional wisdom, Gallup also shows Hillary Clinton with an enthusiasm advantage over Bernie Sanders among Democratic voters.
* Speaking of Sanders, as Rachel noted on the show last night, the Vermont senator's campaign raised an extraordinary $4 million in the two days following Saturday night's caucus victories.
* Though Clinton appears to have an enormous advantage among superdelegates, Sanders' campaign manager, Jeff Weaver, said yesterday there's a "significant number" of superdelegates ready and willing to back the independent senator. Weaver would not say how many, or who these superdelegates are.
* Wisconsin Gov. Scott Walker (R) has thrown his support to Ted Cruz, but if Trump is the Republican nominee, the Republican governor says he'll support him, too.
* Faced with the very real prospect of a contested convention, presidential campaigns are getting more serious about counting delegates. Team Trump, for example, has hired "veteran Republican strategist Paul J. Manafort to lead his delegate-corralling efforts." Manafort helped manage the 1976 convention floor for Gerald Ford.
* On a related note, John Kasich's campaign has hired Michael Biundo and Andrew Boucher, former Rick Santorum aides, to "guide the campaign's efforts in the delegate selection process as well as preparing for the convention."
* And in California, Marco Rubio's name is still scheduled to be on the Republicans' presidential primary ballot in June, though the senator's aides are working on having him removed.