In 2016, yes indeed, Republicans will be defending more seats than in 2010. Thankfully, Tea Party growing pains have focused the party's principles. Reelected Republican Pat Roberts declared after his near miss turned six-point victory:
I've heard my marching orders loud and clear. I will be bold. I will be conservative. And I will be constructive."
In 2012 and 2014, Republicans who had waffled on some issues returned to the fold.
The illegal immigration issue galvanized the base, and brought the Republican Party their eight seat (soon to be nine seat) gain in the US Senate.
Now Republican operatives are turning to 2016.
As stated above, Republicans will be defending more seats, in part because of GOP gains during the 2010 shellacking.
Basing GOP prospects on a 54 seat majority going into 2016, Republicans can lose three seats. I project, however, that West Virginia's Joe Manchin will cross over and become a Republican, since the rest of the Blue Mountain state has gone red. For the first time in decades, Republicans control both chambers of the state legislature. Even the long-term Democrat Nick Rahall finally lost reelection.
So, reassessing GOP numbers at 55, the GOP can sustain a net loss of four seats, and maintain their majority.
Now, which seats are up for reelection in 2016?
These senators have no worry about precisely because the states are safely and strong red, but have been so for a long time. These states have voted straight Republican tickets during Presidential elections, too.
Idaho, Utah, South Dakota, Missouri, Kansas Kentucky, Georgia, Alabama, Ohio, Louisiana, Oklahoma, South Carolina
I will also include Indiana and North Carolina, even though President Obama won these two states in 2008, but those reversals did not signal any meaningful trend, and those states have remained reliably red.
Primary Challenge Seats-Remain GOP
Lisa Murkowski represents Alaska Republican Establishment. Sarah Palin endorsed her Tea Party challenger Joe Miller in 2010, who lost then, and again in 2014 against Dan Sullivan. Miller may try a third time to remove Murkowski, but the senior senator launched a savvy write-in campaign without a hitch then, and she will likely have prepared an extensive campaign war chest for a 2016 fight, abetted by a Presidential nominee who can bring up her chances.
John McCain has already been censured by the state party for supporting amnesty and compromising on key issues. He called Senator Ted Cruz a "whacko bird", but later apologized. He has crossed the aisle one too many times for Arizona Republicans' taste. He will face a stronger primary challenge that year, and may lose in 2016 precisely because of the heated controversy surrounding illegal immigration in a border state. By the way: Red states are not turning purple because of interstate migration, but rather they are staying red. McCain may face a ruby bright primary electorate ready to remove him from office for good. Chances are, with McCain's likely ouster or retirement, another Republican, hopefully a Congressman, will take his place and retain the seat.
John Hoeven won in 2010, replacing a retiring Democrat who read the handwriting on the wall early. Then three years later, he supported the immigration reform bill, which conservative partisans have rallied against. Hoeven may face a primary challenge for supporting that law, but if he survives the fight, and demonstrates a clear record of border security and welfare reform, he may stay in the fight and win.
GOP Swing Seats
Republicans did win these seats in 2010, but by slim margins. They represent blue states, in which President Obama won in 2008 and 2012.
New Hampshire: Kelly Ayotte
Replacing Judd Gregg in 2010, Kelly Ayotte will be the incumbent running to retain her seat this second time. Her support for the Second Amendment while embolden conservatives, but her support for amnesty in the 2013 immigration bill may frustrate voters, too. Even though President Obama won the Granite state in both elections, Ayotte is a homegrown candidate with incumbency on her side. She will likely face a primary challenge, but will have her incumbency to fall back on. Even though she technically represents a swing seat, Ayotte is the least vulnerable of the candidates in this particular list.
Illinois: Mark Kirk
Senator Kirk is a moderate. Pro-choice, pro-gay marriage. He is stiffening his opposition to illegal immigration in recent years, even though he voted for Obamacare-Immigration reform in 2013. He also called for background checks on illegal immigrant minors who have come to this country. Liberal Democratic congressman Luis Gutierrez shamed Kirk for this modicum of national security
I anticipate that Kirk will face a primary challenge as well as a general election assault from a well-funded Democrat. The Illinois Daley machine will be in full force to take back Senator Barack Obama's seat. However, a Republican governor now presides in Springfield following the unprecedented upset of an incumbent Democrat. Bruce Rauner can lay solid groundwork to push against Big Labor while strengthening the Illinois GOP brand. Republicans now hold ten of the states House Seats, which can increase Kirk's chances. Still, Kirk will face a real fight, and he may decline to run. Of all the blue-state Republicans, this seat is the most likely to flip back to a Democrat.
Pennsylvania: Pat Toomey
Toomey was the President of the Club for Growth, an assiduous tax fighter and fiscal disciplinarian. Running during the GOP-friendly 2010 year, Toomey eked out a one point win over Congressman Joe Sestak, who had defeated Republican-turned-Democrat Arlen Specter.
Toomey has stayed true to his fiscally conservative roots, but his drifted toward the center on other issues, like gun control and gay marriage. Part of his concern has been to score support in Democratic bastions in Philadelphia and Pittsburgh, since voter-turnout will be much higher than in 2010.
Wisconsin: Ron Johnson
Unlike Kirk or Toomey, Johnson has not moved to the left on any issues. He has been tried-and-true conservative on every issue that matter in the Republican Party platform. With Wisconsin Governor Scott Walker's third statewide victory in three years, plus the diminished Big Labor funding in the race, Johnson will have less resistance than in 2010. With his own heavy financing, plus support from outside conservative groups and national investments, Johnson can withstand the pressure on an election year.
Florida: Marco Rubio
Rubio angered Tea Party conservatives who had supported him in 2010 when he supported comprehensive immigration "reform". He has backtracked from that bill since then. If he choose to run for President, Rubio pledged to give up is senate seat. Florida has twice gone to Obama in the last two Presidential election cycles, and despite Rick Scott's close reelection over Republican-turned-Independent-turned-Democrat Charlie Crist, Florida remains a purple state whose national influence remains to be seen. If Rubio stays, the seat will more likely stay GOP. Rubio runs, and the seat has a 50-50 chance of going Democratic.
Senate Minority Leader Harry Reid is in big trouble in Washington and his home state. He has picked the wrong fights time and again. He supported amnesty, big bank bailouts, and Obamacare. He faced a weak opponent in 2010, whom he bested by only five points. After six eights years of President Obama, Nevadans will have soured on the Democratic Party brand no doubt. If Nevada Governor Brian Sandoval runs for US Senate, he will win the seat without too much trouble, since he is one of the most popular governor's in the state's history. He just won reelection with 71% of the vote, and his machine defeated Reid's attempt to seat his own son as Lieutenant Governor.
Harry Reid will be fighting against a failed record of Obama policies, obstructionism, and plain, outspoken nastiness. Reid may choose to retire, which will ease GOP pick-up opportunities, as a shallow bench of Nevada Democrats will fight for the general election nod.
Mike Bennett benefited from a weak candidate who had not coalesced Tea Party frustration into a statewide US Senate campaign. That unlikely challenger did win a House seat in 2014, but with party leaders learning from past mistakes, and assessing the full range of necessary characteristics, plus Congressman Cory Gardner's smart and effective win this year, Colorado Republicans will have a strong candidate lined up who can attack Bennett for supporting Obama and open borders, while neglecting the financial and security needs of Colorado voters. Even with an ongoing Presidential election boosting voter turnout, Centennial State voters fed up with the statist status quo will throw Bennett out.
Safe Dem Seats
Assessing all metrics and statistics remaining as they are, with no retirements, Democrats can bank on the following seats staying blue:
Vermont, Connecticut, New York, Maryland, Oregon
Swing Dem Seats
It's very likely that junior US Senator Barbara Boxer will retire in 2016, which will open up the seat to a battle royale between stateside Democratic office holders Gavin Newsom or Kamala Harris, or even Jerry Brown (if he chooses not to run for President).
Washington: Patty Murray
The soccer mom in tennis shoes has turned into a tax-and-spend queen of pork, according to savvy critics. She faced a close contest in 2010 against Dino Rossi, although she prevailed in the end. A president year may buoy her prospects, but with the drag of Obamacare and illegal immigration on her campaign, another strong Republican challenger may be able to oust her, or at least give her another run for her money.
To assess GOP chances of holding the Senate in 2016, we need to focus on blue-state Republicans. According to this list, there are five. If we conclude that the GOP will have fifty-five seats going into 2016, and they lose all five seats, they will have to bank on the Republican nominee wining the Presidency in the general election. This outcome has happened before, in 2000. Bush's Vice President Dick Cheney, as President of the Senate, played the tie-breaking vote which kept Republicans in charge of the chamber. The likelihood of Republicans losing all five seats, however, is remote, just as the possibility of Democrat Joe Manchin switching parties is no certainty, either. Most likely, Kelly Ayotte will survive, if barely. Worse case scenarios will see Kirk lose, or not run and a Democrat win the seat. Johnson will have a strong GOP ground game keeping him place. Combining the vulnerable Republicans winning with one Democrat losing (most likely Harry Reid), and the range of plausible scenarios returns to one clear outcome:
Republicans will hold the US Senate on November 8, 2016.