Here are the changes, explained:

Senate races

-Boxer, like many other senators, has seen her personal polling numbers decline. An independent Field Poll this month had her favorability at 38 percent, with 51 percent unfavorable. Her lesser-known potential GOP opponents have been making headway in the meantime, with former Rep. Tom Campbell (R-Calif.) actually showing a one-point lead on the incumbent in that Field Poll (he’s been within the margin in a few others). But the clincher was this quote from Boxer’s campaign manager after the Field Poll: “We always thought this was going to be a challenging race, and now it's clear this is going to be the toughest Boxer campaign yet.” MOVED FROM “LEAN DEMOCRATIC” TO “TOSS-UP.”

-The open seat in Florida, currently held by placeholder Sen. George LeMieux (R-Fla.), is looking more and more like a potential Democratic pickup opportunity. As the race stands now, former state House speaker Marco RubioMarco Antonio RubioHillicon Valley: Experts worry North Korea will retaliate with hacks over summit | FBI works to disrupt Russian botnet | Trump officials look to quell anger over ZTE | Obama makes case for tighter regs on tech Putting pressure on Trump, House passes bill barring government from doing business with ZTE The Hill's Morning Report — Sponsored by PhRMA — Tensions mount for House Republicans MORE is likely to be the GOP nominee. And Rep. Kendrick Meek (D-Fla.), unlike in early polls against Gov. Charlie Crist (R), is polling close to Rubio in some cases. Rubio has also begun to take his bumps over some personal financial issues, and it’s hard to see him coming out of the primary against Crist’s $7.6 million bankroll without some bruises. Meek has been raising solid money, and he’s also less well-known than Rubio at this point, which could account for his deficit in some polls. Florida is a swing state, and like other swing-state open seats right now, we’re expecting a close race that should start as a toss-up. MOVED FROM “LEAN REPUBLICAN” TO “TOSS-UP.”

-It’s hard not to look at an open seat in Connecticut as at least somewhat competitive, especially with an underdog GOP candidate willing to spend $30 million of her own money. But state Attorney General Richard Blumenthal’s (D) numbers are really good right now, and Republicans are fighting a primary amongst themselves that looks to be very damaging. Blumenthal will still have to run a race, but it’s going to take a lot for either former WWE CEO Linda McMahon (R) or former Rep. Rob Simmons (R-Conn.) to take him down. Polls right now show Blumenthal around 60 percent and holding 20-30 point leads on both of them, which is more than a lot of incumbent senators can say right now. And he’s getting a free pass while the GOP dukes it out. MOVED FROM “LEAN DEMOCRATIC” TO “LIKELY DEMOCRATIC.”

House races

-Rep. Debbie Halvorson (D-Ill.) – from “LIKELY DEMOCRATIC” to “LEAN DEMOCRATIC.” Halvorson’s GOP opponent, Adam Kinzinger, needs to a raise a little more money. But his campaign’s poll showing him up six points after the healthcare vote is encouraging.

-Rep. Mike McMahon (D-N.Y.) – from “LIKELY DEMOCRATIC” to “LEAN DEMOCRATIC.” McMahon faces real problems on both his right and his left after he irritated liberals with his ‘no’ vote on healthcare, and the Working Families Party is talking about running a third-party candidate against him. The easy jog McMahon had against a weak opponent in 2008 makes us forget how tough a district this is, sometimes. And look for a big fundraising number from one of his GOP opponents in the first quarter.

-Rep. Eric Massa’s (D-N.Y.) open seat – from “TOSS-UP” to “LEAN REPUBLICAN.” Things have gone from bad to worse for Democrats in this district. And they are still sorting out who they want to run. A couple of big names have passed, and the baggage that comes with Massa’s exit are enough to push this one toward Republicans. The GOP also got a break when former Rep. Randy Kuhl (R-N.Y.) opted not to run.

-Rep. Tom Rooney (R-Fla.) – from “WORTH WATCHING” to off the list. Rooney’s Democratic challenger, St. Lucie County Commissioner Chris Craft, dropped out last week.