* Via Mark Murray, it’s a tight race on the Republican side:

Donald Trump and Ted Cruz are locked in a tight Republican race – separated by just three points – according to results from a new national NBC News/Wall Street Journal poll. Trump is the first choice of 30 percent of Republican primary voters – followed by Cruz at 27 percent, John Kasich at 22 percent and Marco Rubio at 20 percent.

Last month, the same NBC/WSJ poll found Cruz with a two-point lead over Trump, 28 percent to 26 percent, but that was before Trump’s big wins in South Carolina and Nevada.

Thanks to Kasich, who moved up 11 points, Rubio now holds a fourth place lead, rather than a third place lead, which means he’s gaining #MarcoMentum. (In all seriousness, the polling that really matters for Rubio is in Florida, where he absolutely has to win next Tuesday.) — gs

* CNN’s M.J. Lee ferrets out this interesting nugget from the internals of the new NBC poll:

Contested convention here we come? — gs

* Amber Phillips runs down the state of Trump’s support among Republicans in the Senate:

By our count, the slightest majority — 29 of 54 — have indicated they will support the Republican nominee even if it’s Trump.

There’s one senator so far, Sen. Jeff Sessions (Ala.), who has endorsed Trump. Another 22 have specifically said they will support whoever is the nominee. They include party leaders like Senate Majority Leader Mitch McConnell (Ky.), the Senate’s No. 2, Sen. John Cornyn (Tex.), and Sen. Orrin Hatch (Utah), the most senior Republican senator. Most of the senators in this category say they’ll support Trump for one simple reason: He’s better than Hillary Clinton.

“Any of the candidates we have on their worst day, is better than Senator Clinton on her best,” Sen. Thom Tillis (N.C.) said.

That doesn’t mean Senate Republicans’ support for Trump is a done deal. About a half-dozen senators who indicated or appeared to indicate they’ll support Trump’s nomination also expressed serious reservations about it — especially after Trump took several days to denounce support from a former Ku Klux Klan leader. Several of their comments leave wiggle room for them to back out.

There’s no endorsement quite like “I guess he’s better than a woman who for the last 25 years we’ve said sits at Satan’s right hand.”

* Ian Tuttle brings us the story of The Trump Network, which sure looks like another Trump scam:

In November 2009, Trump, boasting a Midas-gold tie, took the stage in front of several thousand fans at Miami’s Hyatt Regency to debut his latest venture: The Trump Network™, a multi-level marketing operation focused on nutritional supplements. Trump was, as ever, ebullient: “When I did The Apprentice, it was a long shot. This is not a long shot. . . . We are going to be the biggest in the industry.” The Trump Network’s motto was ubiquitous at the event: Discover the Difference between Opportunity and Success.

In reality, people were about to discover the fine line between a multi-level marketing strategy and a pyramid scheme.

Check out the video where Trump shouts into the camera about how this is going to be a great success for everybody, and you don’t want to miss this opportunity.

* David Cay Johnston reports that Donald Trump has used a quirk in the tax code to report negative income in the past, and that might be why he doesn’t want to release his tax returns.

* Dahlia Lithwick argues that with Antonin Scalia’s death, the conservative era at the Supreme Court is over, even without his replacement being seated yet.

* Hillary Clinton has blasted Bernie Sanders for being against saving the auto industry, because he voted against TARP funds in 2009. George Zornick talks to the Democratic senators who, like Sanders, voted against TARP, and they agree with him that it wasn’t about the auto bailout.

* Julia Azari looks at what happens when political parties have splintered in the past, and what lessons that history might hold for The Great Republican Crackup of 2016.

* Michael Brendan Dougherty explains why conservative talk radio supports Donald Trump.

* Philip Bump gets to the bottom of what’s going on with the early votes that have already been cast for the Republican primary in Florida.

* Dara Lind says that Ted Cruz is more interested in winning the nomination than stopping Trump from winning it, and that’s a big problem for the GOP.

* At The Week, I explained why Donald Trump is not going to win over so many working-class whites that he can ride them to victory.

* And social media fails don’t get much worse than this:

The National Republican Senatorial Committee deleted a tweet Tuesday afternoon attacking Rep. Tammy Duckworth (D-IL), a double amputee, for “not standing up for our veterans.”

A slew of Twitter users pointed out the poor wording of the tweet, which was quickly deleted. Duckworth is a U.S. Army veteran of the Iraq War who lost both of her legs in combat and the first disabled woman elected to the House.

Yeah, that’s not good. I certainly hope the 22-year-old staffer who was put in charge of social media at the NRSC — because he gets what the young people are into these days, with their Tweeter and their Snipchat and their Upstagram — will be able to find another job.