Today's installment of campaign-related news items from across the country.
* In New Hampshire this morning, former Massachusetts Gov. Bill Weld (R) launched a presidential exploratory committee, becoming Donald Trump's first primary challenger. For the record, since Watergate, every incumbent president who's faced a credible primary rival went on to lose the general election. (Whether Weld proves to be credible remains to be seen.)
* Sen. Kamala Harris' (D-Calif.) presidential campaign picked up an important endorsement yesterday, when Rep. Barbara Lee (D-Calif.), the former chair of the Congressional Black Caucus, threw her support behind the senator.
* Former Rep. Beto O'Rourke (D-Texas), weighing a possible presidential campaign, has lined up a couple of events in Wisconsin and Illinois -- which is probably not the sort of thing someone eyeing a Senate campaign in Texas would do.
* Speaking of the Lone Star State, MJ Hegar, whose Democratic congressional campaign came up short in November, but who nevertheless impressed many with her candidacy, is leaving the door open to a possible Senate race next year against Sen. John Cornyn (R-Texas).
* The Democratic Party has unveiled a detailed new plan on how presidential hopefuls will qualify for the upcoming debates, and DNC Chair Tom Perez spoke with Rachel about the plan on last night's show.
* With less than two weeks remaining before Chicago's mayoral race, a new poll from the local NBC affiliate shows a very competitive, multi-candidate race.
* The Congressional Leadership Fund, a Republican super PAC closely aligned with House GOP leadership, launched attack ads this week, blasting Reps. Antonio Delgado (D-N.Y.) and Colin Allred (D-Texas) over the "Green New Deal." In reality, neither Delgado nor Allred support the policy, which in turns suggests deceptive 2020 advertising is off to a very early start.