Since we last took a comprehensive look at the 2016 Senate races, a slew of new candidates have jumped in, some promising contenders have dropped out, and intraparty competition has intensified.

Sounds dramatic. Yet what most strikes us is the overall stability, thus far at least, of the Senate picture.

First, Democrats have a plausible but narrow path to a minimal majority, requiring a net gain of four seats if a Democratic vice president is also elected, or five seats if the GOP wins the White House. But as we note below, Democrats need to win the lion’s share of the small number of truly competitive seats on this cycle’s map.

Second, because the route to a Democratic majority is fraught with peril and obstacles aplenty, the Republicans are still more likely to keep the majority than the Democrats are to win it, though it would be a considerable surprise if the GOP’s 54-46 seat margin wasn’t reduced by at least a seat or two. Not losing any net seats probably requires the Republican nominee to not only win the presidency, but capture more than 300 electoral votes in doing so — something no Republican has done since George H.W. Bush in 1988.

Third, if the Republican presidential ticket is triumphant, even if just by a hair, it will be exceptionally difficult, perhaps impossible, for the Democrats to take over the Senate; the wind would be at the backs of GOP Senate candidates even in the handful of blue states where a Republican holds the Senate seat.

Fourth, if the Democratic presidential ticket is elected, Democrats in the tightest Senate races will benefit — nearly all the key Senate races at this point are in plausible presidential battlefields (with the exception of Illinois, which almost certainly will comfortably support the Democratic White House nominee). While it is possible for the Democrat to win the presidency and the Republicans to hold the Senate, it becomes ever more perilous for the GOP majority as the Democratic presidential vote margin grows. In other words, a Democratic squeaker win for the presidency might not capture the Senate, but a victory of several percentage points may well do the trick.

Fifth, to this point, Republican Senate incumbents have mostly avoided serious, divisive primary challenges from the right. Sens. John McCain (R-AZ) and Jerry Moran (R-KS) may prove to be exceptions, but both begin as solid favorites. After the internecine battles that bruised Republican Senate nominees the last several cycles, this more tranquil environment must surely thrill the GOP leadership — not to mention the Republican incumbents up for reelection. And remember, for all the hype last year, no incumbent GOP senator lost a primary in 2014.

Sixth, Democrats are getting a taste of factional fighting in several states. California and Maryland are Democratic enough that the eventual party nominee will likely be fine — although Gov. Larry Hogan (R-MD) is proof that the principle has exceptions, at least in a low-turnout midterm election. It’s in Florida where Democrats need to worry, with good reason. We’ll explain later on.

All this aside, the Crystal Ball does have two ratings changes in important Senate contests. We are moving Illinois from Toss Up to Leans Democratic, and we are moving North Carolina from Leans Republican to Likely Republican. An update on these critical races and other key Senate matchups follow.

Table 1: Crystal Ball Senate rating changes

Illinois: Kirk’s coattail conundrum

Sen. Mark Kirk (R-IL) has a serious mountain to climb if he wants to hold onto the seat he won in 2010. And that peak’s name is “presidential coattail.”

There are seven Republican-held seats in states that President Barack Obama won in 2012 that are up for election in 2016. Of those, Illinois is the most Democratic by presidential vote, and it’s not close. In 2012, Obama won 58.6% of the two-party vote in the Land of Lincoln (a noticeable drop from 62.7% in 2008; he likely benefited more from being a home-state candidate in 2008 than 2012). The next closest of the seven states in question is Wisconsin, where Obama won 53.5% of the two-party vote in 2012. That five-point difference demonstrates just how Democratic Illinois is, and it means that Kirk is going to have to run well ahead of the eventual GOP presidential nominee to have any chance of winning.

But history doesn’t provide a great deal of encouragement for the Kirk campaign. As we discussed back in March, the vote percentages in Senate races have become increasingly correlated with the presidential result. Correspondingly, the same party increasingly wins both contests in a given state. In fact, the percentage of straight-ticket results in concurrent presidential and Senate elections grew from 69% in 1992 to 81% in 2012.

If we dig into the results most germane to Kirk’s chances — Republican incumbents seeking reelection in blue states during presidential cycles — the numbers tell a mixed but fairly bleak story for Kirk. Going back to the 2000 election, 17 blue-state Republican incumbents have run for reelection. The data for these senators are laid out in Table 2; all figures in the tables are based on the two-party vote for Senate and president in those four presidential cycles.

Table 2: Incumbent Republican senators seeking reelection in states won by the Democratic presidential nominee, 2000-2012

Note: *Signifies appointed incumbent; senators colored in orange lost reelection.

On the one hand, these 17 incumbents ran an average of 8.7 points ahead of the GOP presidential nominee in the two-party vote. Only two of them didn’t run ahead of the presidential ticket. Those data points suggest that Kirk does have a shot at holding on — and we should reiterate that he does. On the other hand, only eight of the 17 Republican incumbents won reelection, and the median incumbent only ran 5.7 points ahead, perhaps a more useful number with such a small sample size. (Averages can shift dramatically if there are very large or small observations in the data set; for example, Vermont Republican Sen. Jim Jeffords ran 27.5 points ahead of George W. Bush in the 2000 cycle.)

So how much of Illinois’ vote will the Democratic presidential nominee win in 2016? Impossible to say exactly, of course, but John Kerry won 55.2% of the state’s two-party vote in 2004, which serves as a useful measuring stick — it’s the lowest Democratic take in the 2000-2012 period. If Kirk were to perform at the median level of recent times, he would be running 5.7 points ahead of 44.8% for the Republican presidential ticket’s two-party vote, which would put him at 50.5%, just ahead of his Democratic opponent’s 49.5%. Safe to say, Kirk will have very little margin for error to win.

Given our previous Toss-up rating, we can still see Kirk overcoming Democratic coattails. After all, prior to being elected to the Senate, Kirk held a Democratic-leaning House district in suburban Chicago and has long had a moderate profile, the only kind a Republican statewide official can really have in a fairly blue state like Illinois in a presidential year. But now some recent statements have put Kirk in hot water, giving Democrats plenty of ammunition to work with. Some examples include referring to unmarried Sen. Lindsey Graham (R-SC) as his “bro with no ho,” and his interest in making sure “that the black community is not the one we drive faster through.” Using a poor choice of words once is one thing; doing so repeatedly — he recently said Obama wants “to get nukes to Iran” — has become all too common for Kirk. Part of the reason we’re moving Illinois now — after all, Kirk’s coattail problem is not new — is that we feel Kirk needs to run a near-perfect race to win, and he has not shown that ability thus far.

It remains to be seen who will face off against Kirk next November, but Rep. Tammy Duckworth (D, IL-8) is the favorite in the Democratic nomination race. Former Chicago Urban League President and CEO Andrea Zopp (D) is going to try to give Duckworth a fight in the primary, but the congresswoman has the endorsement of the Democratic Senatorial Campaign Committee, a signal that she is the choice of much of the party establishment. We still have some uncertainty about Duckworth’s strength as a statewide candidate, but Kirk’s foot-in-mouth troubles and the state’s Democratic lean surely help her chances. But we’ll keep an eye on intraparty strife here — the Duckworth-Zopp faceoff could get nasty.

With Illinois’ new Leans Democratic rating, it joins Wisconsin as the two Republican-held Senate seats where we currently view Democrats as small favorites in 2016. In the Badger State, Sen. Ron Johnson (R) will almost certainly face ex-Sen. Russ Feingold (D) in a rematch of their 2010 contest, but Johnson may be too conservative for his state in a presidential cycle. He too will have to deal with Democratic coattails in a state that hasn’t backed a GOP presidential nominee since 1984. Kirk has a better ideological profile for his Democratic-leaning state than Johnson does for his, but the Land of Lincoln is a darker shade of blue.

North Carolina: Nobody wants a piece of Burr

The good news for Republicans is that Sen. Richard Burr (R-NC) looks stronger than ever in the Tar Heel State, which has led us to move his contest to Likely Republican. Burr’s improved position comes mainly because the state’s top Democrats have thus far passed on the race. Ex-Sen. Kay Hagan (D), who narrowly lost to now-Sen. Thom Tillis (R) in 2014, and state Treasurer Janet Cowell (D) have both opted against Senate bids. U.S. Secretary of Transportation Anthony Foxx (D), another potential Democratic recruit, has also said he won’t run.

Although there’s time left for someone to change his or her mind — à la now-Sen. Cory Gardner (R-CO), who initially passed on a 2014 run only to end up winning a U.S. Senate seat — Burr’s fundraising head start will make a challenge less and less attractive as time goes on. While polling has often showed the low-key Burr to be surprisingly unknown for a man first elected statewide in 2004, horserace hypotheticals have routinely shown him leading all comers in 2016.

While the DSCC is projecting confidence about the party’s ability to take on Burr, the fact remains: Democrats have no candidate. Moreover, North Carolina has a slight Republican lean at the presidential level, which should assist Burr. Since 2000, of the 52 Republican Senate incumbents who have faced a Democratic challenger in a reelection bid, 38 have run ahead of the presidential nominee in the two-party vote. Unless Democrats can field a strong candidate — Sen. Elizabeth Dole (R-NC) ran behind John McCain while losing to Hagan in 2008, for example — Burr may be the next to accomplish this feat. Keep an eye on this race, though — we won’t hesitate to make the rating more competitive if a strong challenger emerges. Yet history shows Burr is a politician who has exceeded expectations in both of his prior Senate contests.

The rest of the Senate picture

Moving Illinois out of the Toss-up column leaves only two pure coin flips among the 34 Senate races being contested this year: open seats in Florida and Nevada. Recent developments have made each race even more intriguing.

In the Sunshine State, Democrats are miffed that Rep. Alan Grayson (D, FL-9) has entered the primary against establishment favorite Rep. Patrick Murphy (D, FL-18). Murphy represents a Mitt Romney-won congressional district and is cultivating the same moderate image that has helped recently successful statewide Florida Democrats, such as durable incumbent Sen. Bill Nelson (D) and the consistently successful Bob Graham (D), a former senator and governor. Grayson, meanwhile, represents safe Democratic territory and is best known for bomb-throwing rhetoric and personal foibles. Murphy’s path to victory is to emphasize the personal, like Grayson’s bombastic comments, recent messy marriage annulment, and financial questions, while Grayson will aggressively run to Murphy’s left. In addition to voting with Republicans on issues like the Keystone XL pipeline, Murphy is a former Republican. Grayson probably starts with a small lead thanks to better name ID, but it’s a Toss-up primary — both represent just 1/27th of the big state in the House, so they both have lots of work to do. Murphy’s the next great hope for Democrats in Florida: If he is to emerge, he’ll have to earn it despite his broad national and state party backing. Or perhaps, in the person of Grayson, Florida will give Democrats their Todd Akin (R-MO) or Richard Mourdock (R-IN) — recent Republican Senate nominees who won tough primaries only to appear extreme and fall apart in the general election.

One wild card: The Florida Supreme Court has ordered the Republican-controlled legislature to redraw the state’s congressional map. On balance, the changes might lead to the Democrats netting a seat in Florida, but the already GOP-leaning panhandle district of freshman Rep. Gwen Graham (D, FL-2) may be redrawn in a way that makes it unwinnable for her. Might she jump into the Senate race, too? Among Florida politicos, Graham is viewed by many as potentially the Democrats’ most formidable candidate. The first-term representative and daughter of the aforementioned Bob Graham has a moderate profile like Murphy’s. Ironically, if she does enter the Senate race, it could ultimately help Grayson — and the GOP. Graham is also a potential Democratic gubernatorial contender in 2018, or perhaps she could run for Nelson’s Senate seat if he decides to retire next cycle (though Nelson has insisted he’ll run again; he’s currently recovering from surgery for prostate cancer).

The pending Florida re-map is having an effect on the Republican Senate primary, too. Rep. David Jolly’s (R, FL-13) swing district is likely to become more Democratic after redistricting, so he is now running for Senate.* Similar to Graham on the Democratic side, Florida insiders view Jolly as the strongest general election candidate in the crowded Republican field. Besides Jolly, Rep. Ron DeSantis (R, FL-6), Lt. Gov. Carlos Lopez-Cantera (R), and businessman and veteran Todd Wilcox (R) have all declared their candidacies. Additionally, Rep. Jeff Miller (R, FL-1) is a likely entrant, while former state Attorney General Bill McCollum (R) is also considering a bid. DeSantis is a favorite of anti-establishment conservative groups like the Club for Growth and Senate Conservatives Fund, and Democrats would like to run against him because they believe they can categorize him as a right-wing candidate. Meanwhile, the DeSantis team is hopeful that he can become a consensus candidate in the GOP primary, starting with their base of support on the right and making inroads with the party establishment. A model might be now-Sen. Ben Sasse (R-NE), who over the course of last year’s primary campaign appealed to both the outsider right and the party establishment as competitors fell by the wayside. As Florida doesn’t use a runoff system with party primaries (the state eliminated the practice before the 2002 election cycle), it won’t take a high percentage to win the GOP nomination if there are four or more credible candidates.

Florida could decide control of the Senate and the White House next year, and at this point, it’s anyone’s game in both statewide races.

In the Silver State, there’s not much primary intrigue. Former state Attorney General Catherine Cortez Masto (D) should be the Democratic nominee, and Rep. Joe Heck (R, NV-3), who represents a swing seat, also appears to have a clear path to his party’s nomination. Masto was probably the Democrats’ best recruit, and Heck was the next-best GOP alternative to popular Gov. Brian Sandoval (R), who never appeared close to running.

Assuming they keep the White House — a big assumption — Democrats would need to net four seats to win the Senate, and the key word is “net.” Holding their own vulnerable seats is the first step. Nevada will be tight; Democrats are favored in the other nine seats they already control on this cycle’s slate, although Colorado just Leans Democratic. Still, Sen. Michael Bennet (D) must be thrilled that Republicans have been unable to entice a top-tier contender into the race. But just like North Carolina, it’s early. We could imagine moving Colorado to Likely Democratic using the same logic that moved North Carolina to Likely Republican, but Colorado could end up being more of a presidential toss-up than North Carolina. A GOP trend in fall 2016 might make the path for Republicans in Colorado easier than it seems to be now. However, that’s speculation, and the hard evidence for the moment shows that Bennet, just like Burr, has seen his position improve.

If Democrats hold Colorado and Nevada, their best offensive targets are, as mentioned above, Illinois and Wisconsin. Winning those two would get them halfway to their goal, and taking Florida would get Democrats three-quarters of the way.

Republicans remain favorites — though only slightly in a few — in every other race on the board. If Gov. Maggie Hassan (D) challenges Sen. Kelly Ayotte (R) in New Hampshire, that contest would become a Toss-up. Republicans are releasing internal polls and running ads against Hassan to try to dissuade her from running. She is in the midst of a budget battle that might last months, but as the clear Democratic frontrunner, Hassan can freeze the field into next year if she wants. Ayotte would probably be a decent favorite against any other Democrat unless the state votes substantially Democratic for president.

In Pennsylvania, Democrats have been seeking an alternative to 2010 nominee Joe Sestak (D) to run against Sen. Pat Toomey (R), and it appears one has finally emerged: Katie McGinty (D), chief of staff for Gov. Tom Wolf (D), is expected to resign her position on Thursday and declare her Senate candidacy sometime in the next few weeks. Given the Democratic establishment’s distaste for Sestak, the Democratic primary could be acrimonious and expensive, perhaps serving as a nice undercard to the Florida Democratic primary. Still, McGinty doesn’t exactly have a sterling electoral track record: She got just 7.7% in last year’s gubernatorial primary, finishing last among four candidates and 50 points behind Wolf. Sestak remains a favorite to win his party’s nomination, making a Toomey-Sestak rematch the likeliest outcome. A Hillary Clinton presidential victory could help make Sestak a senator despite his poor reputation with state and national Democrats, who see him as aloof and difficult to work with.

A Quinnipiac poll has shown former Gov. Ted Strickland (D) leading Sen. Rob Portman (R) in Ohio, but we’re skeptical. The race should be quite competitive, and Clinton could help Strickland over the finish line, but we still see the well-funded Portman with a small edge. Ohio is a place where Obama’s absence from the ticket could cost Democrats a couple points worth of black turnout in places like Cleveland and Cincinnati, which might be the difference between winning and losing. Strickland still needs to win a primary against Cincinnati City Councilman P.G. Sittenfeld (D), though there’s not much indication that Strickland is in any trouble. However, we’re hearing growing dissatisfaction from some Ohio Democrats about the state and national party’s efforts to push Sittenfeld out of the race.

Beyond that, Democrats will hope for primary chaos in places like Arizona, where McCain is being challenged by far-right state Sen. Kelli Ward (R) and where Democrats have a strong potential nominee in Rep. Ann Kirkpatrick (D, AZ-1), and Indiana, where ex-Rep. Baron Hill (D) hopes a crowded primary produces a subpar, damaged GOP nominee. Missouri is another fringe Democratic target, but the veteran, wily Sen. Roy Blunt (R) would have to make some serious mistakes to open the door for his likely opponent, Missouri Secretary of State Jason Kander (D).

States not mentioned so far do not, at the moment, offer much intrigue for next year’s general election. As of now, only eight of 34 Senate contests feature the competitive Leaning or Toss-up ratings. Democrats need to win six of those eight to force a 50-50 tie in the Senate, which they hope a Democratic vice president will break in their favor.

Map 1: 2016 Crystal Ball Senate ratings

*As noted on Twitter and on our Crystal Ball website, we are not making any preemptive House rating changes in response to the Florida redistricting fiasco. We will wait for a new map to emerge before we do that. However, we are moving Jolly’s FL-13 from Likely Republican to Toss-up, because it is now an open seat divided evenly between the parties. Most observers believe the district will get more Democratic in redistricting, and it appears that former Gov. Charlie Crist (D) will likely run for the redrawn seat. Crist, a St. Petersburg resident, remains popular in the Tampa Bay area. Either or both of those developments could push the seat further toward the Democrats — stay tuned.

Table 3: Crystal Ball House ratings change