Democrats hope, and Republicans fear, that Donald Trump is tilting the Senate battleground map away from the GOP in 2016. But the biggest wild card in the race for Senate control is Marco Rubio.

Calls for Rubio to run for his Florida Senate seat again, reversing his decision to forego reelection when he ran for president in 2015, have reached a fever pitch in recent weeks, with Lt. Gov. Carlos Lopez-Cantera — a GOP candidate and friend of Rubio’s — joining pleas from Senate Majority Leader Mitch McConnell and other top party leaders. Republicans have grown concerned that their primary field seeking to replace Rubio did not have what it took to win the 10-week general election sprint after the late August primary.


Rubio, with his national reputation and fundraising connections, would ease those concerns — though he likely wouldn’t guarantee a Republican victory. Florida is still a tightly divided state, and the bulk of the Senate map is set, though Donald Trump’s hostile takeover of the GOP is tilting some races.

Strategists wonder whether Trump might just help the GOP in less-diverse states like New Hampshire and Missouri, while Republicans running in regions with significant shares of Latino and other minority voters may have more electoral backlash to fear.

Democrats remain confident about defeating Illinois Sen. Mark Kirk and Wisconsin Sen. Ron Johnson, while the presidential swing states of Florida, New Hampshire, Pennsylvania, Ohio and Nevada make up the core of the map. They’re followed by a trio of second-tier states — North Carolina, Missouri and Arizona — as well as Colorado, which is technically a GOP pickup opportunity despite the Republican field’s weaknesses there.

Yet despite their Trump troubles, Republicans do have some advantages of their own. Their well-funded outside groups have put Democrats on defense from Wisconsin to Ohio to New Hampshire, where they have already put millions of dollars behind attack ads.

Rubio has until June 24, Florida’s filing deadline, to make his decision. In the meantime, here are the 2016 Senate races, ranked in order of each seat’s likelihood of switching parties in November:

1. Illinois — GOP Sen. Mark Kirk running for reelection (Previous ranking: 1)

Kirk is ensconced at the top of this list, and there may be little his campaign can to do to change that, given his state’s Democratic lean. Democratic nominee Tammy Duckworth shrugged off a primary challenge in March, and the three-term congresswoman has more money in her campaign account. Most notably, GOP super PACs have left Illinois off their early target lists for outside spending.

Against that backdrop, Kirk’s campaign has hammered on a personalized issue rather than a national one: Duckworth’s upcoming trial, a civil lawsuit filed by her former employees at the Illinois Department of Veterans Affairs. Kirk also got significant attention for un-endorsing Trump, who is likely to lose Illinois by a huge margin. But Kirk will have to keep balancing between keeping base Republicans and moderate swing voters happy for the rest of the campaign.

2. Wisconsin — GOP Sen. Ron Johnson running for reelection (2)

Johnson is running a strong campaign, but the fact remains that even the best effort might not be enough to offset Wisconsin’s blue lean in presidential years, as well as Democrat Russ Feingold’s name-identification advantage. While a few surveys have shown Johnson within the margin of error, Feingold has led every single public poll so far.

Feingold also continues to outraise the incumbent Republican. He has $6.4 million on hand to Johnson’s $5.5 million. But unlike Kirk, Johnson already has plenty of help from GOP outside groups, with more likely coming. Ads from groups in the Koch network have put Feingold on the defensive about his record on veterans’ issues, and the Club for Growth is also prepared to spend heavily to help Johnson. Two super PACs dedicated to Johnson’s candidacy exist, and one has already begun airing ads.

Johnson is essentially attempting to paint Feingold as the incumbent. His first ad of the campaign focused on his business experience, without a single mention of his record in the Senate. Republican releases routinely put “Ron Johnson” against “Senator Feingold.” But the labels that may matter most, “Democrat” and “Republican,” put Johnson at a disadvantage.

3. Florida — Open, GOP Sen. Marco Rubio retired to run for president (4)

Republicans are begging Rubio to run for reelection — to the point that GOP leaders are even sabotaging their own primary field to make the case. National Republicans believe the existing field of Reps. David Jolly and Ron DeSantis, Lt. Gov. Carlos Lopez-Cantera, and businessmen Carlos Beruff and Todd Wilcox doesn’t include a candidate who has shown what it takes to run a statewide race in Florida.

At the same time, outside Republicans are ecstatic with the number they’ve done on Democrats’ preferred candidate, Rep. Patrick Murphy, over the last few weeks. They’ve caught him embellishing his resume and unspooled reels of opposition research to portray him as “privileged Patrick.” Murphy also still must bypass Rep. Alan Grayson in the Democratic primary. Grayson has ethical issues galore, but can also outflank Murphy on the left on any number of issues. President Barack Obama’s endorsement of Murphy is likely to be key.

If Rubio reenters the contest, it’d be easy to see this race fall in the rankings. But with opposition to Trump likely to drive turnout among the state’s plentiful African American and Hispanic voters, an open Florida Senate seat now looks more likely to end up in Democratic hands than New Hampshire’s.

4. New Hampshire — GOP Sen. Kelly Ayotte running for reelection (3)

Ayotte and Democratic Gov. Maggie Hassan are running neck-and-neck, and operatives on both sides expect that to persist through the fall. Ayotte’s relationship to Trump is one to watch: Trump won her state’s primary by a huge margin, but Ayotte has reportedly spoken up about the problems Trump generates for down-ballot candidates behind closed doors.

Ayotte’s team has also been aggressive in attacking Hassan over a sex-abuse scandal at the prep school where her husband served as headmaster and for taking trips out of the state to raise cash. GOP outside groups have attacked Hassan relentlessly; One Nation recently started airing ads hitting the governor for not doing more to tackle the state’s heroin epidemic.

New Hampshire, one of the whitest states in the country, isn’t the type of state where Trump totally ruins GOP hopes. But Ayotte’s reelection bid against another popular statewide elected official was always going to be an uphill fight, and Senate Majority PAC has already started tying Ayotte to Trump in TV ads.

5. Pennsylvania — GOP Sen. Pat Toomey running for reelection (5)

Toomey, a favorite of the Koch network, the Chamber of Commerce and the Club for Growth, looks set to get help from the full breadth of the GOP coalition. Those outside groups also believe they can define Democrat Katie McGinty using everything from her long career in government and consulting to a recent false claim that she was the first member of her family to go to college. Democratic outside groups have had to buck her up, from the DSCC’s big primary spending to a recent (and rare) contrast ad from Senate Majority PAC.

But Democrats are still optimistic: Republicans haven’t won Pennsylvania on the presidential level in decades, and they believe attacking Toomey for Wall Street ties (the other half of that Senate Majority PAC ad) will be potent come November.

Toomey has also been among the more careful Republicans when it comes to Trump, writing a skeptical op-ed after he clinched the nomination that could make breaking with his ticket easier if such a move proves necessary.

6. Ohio — GOP Sen. Rob Portman running for reelection (7)

Ohio might be the epitome of the 2016 Senate campaigns. Portman, who has $13 million in the bank, is a well funded GOP incumbent. Former Gov. Ted Strickland, who has struggled to raise money and whose long tenure in government makes him an opposition researcher’s dream, has struggled somewhat as a Senate candidate.

And there’s lot of Democratic optimism, because Clinton is favored to beat Trump in a state Democrats have won twice in a row on the presidential level. Strickland’s campaign has also zeroed in on Portman’s long pro-trade history, which could become a wedge issue for voters drawn to Trump’s “America first” positioning.

But Portman’s campaign has made massive investments in data, digital and field, which it hopes to use to peel off Clinton voters one at a time by highlighting Strickland’s jobs record as governor and his support for the Iran nuclear deal.

7. Nevada — Open, Democratic Sen. Harry Reid retiring (6)

Former state Attorney General Catherine Cortez Masto is running to be the first Latina ever elected to the Senate, a potent message in a year where Hispanic voters are expected to flock to the polls to reject Trump. Her first television ads have put the focus on her large Hispanic family and her father’s immigrant-to-riches story. But her campaign has been cautious on policy, relying on demographics and biography to lift her over the top.

GOP Rep. Joe Heck looks set to easily clear a Tuesday primary challenge from Sharron Angle, the 2010 nominee who ruined GOP hopes of winning this seat six years ago. But this race has slipped down the flip list because its demographics were already bad news for Republicans — and Trump looks set to make the situation worse.



8. North Carolina — GOP Sen. Richard Burr running for reelection (10)

North Carolina was a Senate afterthought earlier this year, but its diversity is prompting Democrats to give Burr’s seat a fresh look as they figure out their fall priorities. Priorities USA’s $9 million buy in the state is evidence of that, and Burr has low name identification. Democrats believe the Senate race is within the margin of error.

Sens. Richard Burr and John McCain both are at risk of losing their seats in November. | AP Photo

But Deborah Ross, the Democratic candidate, may need all the help she can get. Republicans believe they could make attack ads out of practically every action she took as former chair of the state ACLU. The NRSC debuted an attack ad on cable last weekend slamming Ross for “work[ing] to prevent sex offenders from registering with local authorities.”

9. Missouri — GOP Sen. Roy Blunt running for reelection (9)

Democrats like their candidate in Missouri: They say Afghanistan vet and Secretary of State Jason Kander provides a solid contrast to Blunt, a longtime politician. And some Republicans worry Blunt isn’t running the sharpest campaign.

But Missouri is also a state that has been trending away from Democrats nationally, unlike North Carolina. Kander, on paper, is a better candidate than Ross. But Democrats are increasingly concerned that demographics may negate any edge that might provide.

10. Arizona — GOP Sen. John McCain running for reelection (11)

Latino-heavy Arizona is a prime example of a state where Trump endangers Republicans — and McCain has admitted as much. On the flip side, the key to surviving an anti-Trump wave would be developing a personal brand, and there may not be a single senator as well-known as McCain, the original maverick. Fellow Republicans believe McCain should easily brush aside a primary challenge from former state Sen. Kelli Ward, though McCain’s super PAC has had to spend money opposing her.

Democratic Rep. Ann Kirkpatrick broke $1 million for the first time in a quarter in the first three months of the year, but also spent about $600,000 far ahead of her expensive fall battle with McCain. Overall, Democrats have been pleased with her performance on the trail and think she’s in position to ride an anti-Trump wave, should one crest in November.

11. Colorado — Democratic Sen. Michael Bennet running for reelection (8)

Five Republicans are battling for a chance to take on Bennet, who has $7.6 million in the bank, but they all lag in fundraising, name ID or both. And national Republicans are beginning to lose hope they can unseat the incumbent, whose favorability numbers are weaker than ideal.

Businessman Robert Blaha and former Colorado State University athletic director Jack Graham, both first-time candidates, have both poured in $1 million of their own money into their campaigns to introduce themselves to the state, while former Aurora City Councilman Ryan Frazier, former state Rep. Jon Keyser and El Paso County Commissioner Darryl Glenn have all struggled to raise resources. Blaha, Keyser and Frazier also nearly failed to make the primary ballot, having to rely on legal action to secure their spots. Meanwhile, Bennet has spent hundreds of thousands of dollars per week on positive ads boosting his image.

12. Iowa — GOP Sen. Chuck Grassley running for reelection (unranked)

Grassley was once considered invincible, and he still may be — but he’s watching his back. After the death of Supreme Court Justice Antonin Scalia, Democrats thought they could turn his obstruction of Obama’s Supreme Court nominee into a defining issue in the race and recruited Democratic Lt. Gov. Patty Judge.

So far, there’s no polling to indicate Judge is on the verge of a massive upset, and Democrats believe she needs to raise more money to have a real shot. But in a state Obama won twice, it’s not hard to imagine how this race could get competitive.

13. Kentucky — GOP Sen. Rand Paul running for reelection (14)

The national Republicans who fretted about Paul’s reelection while he was running for president have calmed down. Democrats have also found a solid candidate in Lexington Mayor Jim Gray, who has impressed them with a combination of self-funding and fundraising. But GOP Gov. Matt Bevin’s easy win in 2015 shows it will take some major mistakes from Paul for Gray to have a shot.

14. Arkansas — GOP Sen. John Boozman running for reelection (13)

Boozman was yet another candidate national Republicans worried about last fall, but he has picked up his fundraising and silenced complainers in D.C. Like Paul, he faces a legitimate candidate in former U.S. Attorney Conner Eldridge, who has picked his spots bringing national attention to the race. Former Democratic Sen. Mark Pryor’s huge defeat in 2014 was a sobering experience for Arkansas Democrats, though.

15. Louisiana — Open, GOP Sen. David Vitter retiring (15)

National operatives in both parties admit they are paying little attention to this contest, which is almost certainly heading to a runoff after Election Day. Republicans have four legitimate candidates: Reps. Charles Boustany and John Fleming, retired Col. Rob Maness and state Treasurer John Kennedy. Kennedy has led early polling thanks to a major name ID advantage, but there are some doubts he can legally move money from a state account to a super PAC, a key part of his campaign strategy.

Local Democrats are looking to coalesce around Public Service Commissioner Foster Campbell, who has the backing of Democratic Gov. John Bel Edwards — and has reassembled much of his campaign team. But it took a perfect storm for Edwards to triumph in 2015, and there doesn’t appear to be a GOP candidate in the race with Vitter’s personal, party label-defying vulnerabilities.

Visit the Campaign Pro Race Dashboard to track the candidates and consulting firms engaged in the top House, Senate, and gubernatorial races of 2016.