It didn’t take long for vulnerable Republican senators to start bucking their new majority’s party line.

Just three weeks into Mitch McConnell’s reign as Senate majority leader, he’s already confronting the challenges of running a caucus filled with blue-state Republicans who face reelection next year. They’ve begun departing from the GOP stance on issues like energy and climate change — a move that lets them espouse independence back home, but also exposes divisions that are bound to intensify as 2016 draws nearer.


The Senate’s dynamic was on display in a series of amendment votes over the last week on the Keystone XL oil pipeline: New Hampshire Sen. Kelly Ayotte, one of the Democrats’ top targets in 2016, repeatedly broke with her party, including by opposing efforts to hamper Obama’s international climate negotiations. Illinois Sen. Mark Kirk was the lone Republican to back regulations on petroleum coke, a byproduct from oil refining. And conservative Pennsylvania Sen. Pat Toomey was one of 15 Republicans to endorse a statement that humans contribute to climate change.

Another defector, North Carolina Sen. Richard Burr, was the only Republican to vote for a Democrat-backed mandate that the pipeline be built with U.S. steel. “It’s real simple,” he said proudly. “I’ve been for ‘Buy America’ every time it’s come up in the Senate.”

Democrats lost most of those amendment battles, and the Senate is expected to eventually pass the pro-Keystone bill with support from all of the chamber’s 54 Republicans. The pipeline also has Democratic supporters such as Colorado Sen. Michael Bennet — himself vulnerable in 2016 — who opposed a Democrat-led filibuster that stalled the measure Monday night.

But the early test on Keystone shows one of the major juggling acts McConnell must handle as he begins to chart an aggressive course for his majority, with more tough votes looming on the budget, taxes, trade and foreign policy.

If McConnell goes too far to the right, he could lose swing-state GOP senators who need to moderate on issues that resonate in their backyards, especially during a presidential election year that’s expected to bring a surge of Democratic turnout. But if McConnell tries to move to the center on issues that play well in Ohio or Wisconsin — where GOP Sens. Rob Portman and Ron Johnson face reelection, respectively — he could have a hard time reconciling the Senate’s legislation with what comes out of the conservative House.

One bright spot: The defections will help GOP senators rebut Democratic accusations that they’re mere foot soldiers for their party’s leaders in an unpopular Congress. Republican leaders hope their endangered senators will defect on less controversial issues but ultimately fall in line for the bulk of the party’s agenda, starting with Keystone and continuing into this spring’s budget fight.

“Not everyone is going to vote like a red-state senator from Texas,” said Sen. John Cornyn (R-Texas), the chief vote-counter for his conference. “That’s just part of our diversity and regional differences. But I’d say we’re pretty darn unified and making good progress.”

Indeed, the Senate GOP Conference’s ideological spectrum includes a conservative wing marked by the likes of Ted Cruz of Texas and freshman James Lankford of Oklahoma, along with a handful of moderates like Susan Collins of Maine and Lisa Murkowski of Alaska. In the middle is McConnell, who has 54 votes if he can keep his caucus united, six shy of breaking a Democratic filibuster and 13 short of overriding a veto.

What makes this class of Republican senators particularly vulnerable is the expectation that they will be running in a far different climate in 2016. When they won their elections in 2010, the political environment heavily favored Republicans, as the rise of the tea party and fears over Obamacare drove GOP turnout in the midterm elections. But with the presidential race driving a larger number of voters in 2016, and Democrats hopeful that Hillary Clinton will draw women to the polls, Republicans could face a daunting path to holding the majority. The GOP has 24 Senate seats in contention, compared with the Democrats’ 10.

The dynamics put blue-state Republicans like Kirk in a tricky spot. To pull off a victory, the former 10-year House veteran will have to show he can work with Democrats and espouse moderate credentials, without leaving himself vulnerable to a primary challenge.

So far this year, he has balked at his party’s efforts to derail Obama’s executive actions on immigration through the Homeland Security spending bill. He joined Democrats on a number of early votes, including siding with fellow Illinois Sen. Dick Durbin in favor of regulating petroleum coke, an issue of importance on Chicago’s South Side. And he broke with Republicans by backing an amendment offered by his close friend, West Virginia Democrat Joe Manchin, calling on the Senate to invest in so-called clean coal technology.

In an interview, Manchin indicated he may endorse Kirk’s reelection bid. “He’s my friend, and I will do whatever my friend thinks I could do to help him,” Manchin said.

While allowing Republican senators to showcase their independence, the uptick in action on politically charged amendments also puts them at risk for seeing their votes turned into 30-second attack ads.

Blue-state Republicans are also bound to face attacks if they vote against populist-tinged issues — such as when the GOP united to block an amendment by Sen. Ed Markey (D-Mass.) that would have required Keystone’s oil to be used in the U.S.

“It’s clear there are any number of Republican senators who will be spending lots of time desperately trying to distort their irresponsible records,” said Justin Barasky, spokesman for the Democratic Senatorial Campaign Committee.

The politically charged nature of Senate debate was a big reason why now-Minority Leader Harry Reid (D-Nev.) shielded vulnerable Democrats from sensitive votes in the last Congress. A number of Democrats privately argued that casting politically toxic votes on issues like Obamacare and taxes could hurt their reelection efforts. But others, like former Sen. Mark Begich of Alaska, who lost his reelection bid last fall, said having more votes would have allowed red-state Democrats to distinguish themselves from an unpopular White House.

In the new Senate, McConnell’s caucus appears to be taking Begich’s advice.

Ayotte, who won her 2010 Senate primary with an endorsement from Sarah Palin, cast a series of votes in the opening month of the new Congress that broke sharply from her caucus. The former New Hampshire attorney general opposed a Toomey proposal that would have exempted power plants that burn waste coal from certain federal emission limits. She opposed an effort by Utah Sen. Mike Lee to make it easier to drill for oil and gas on public lands. And she opposed a proposal by a member of her party’s leadership, Missouri Sen. Roy Blunt, to hamstring international climate agreements reached by the Obama administration, including a recent pact with China.

Ayotte spokeswoman Liz Johnson said the senator’s votes “are consistent” with her “long record” of “standing up for clean air and crossing party lines to protect New Hampshire’s environment.”

Other GOP defections took Senate insiders by surprise, particularly on climate change. In a vote last week, 15 Republicans joined with Democrats to state that climate change is “real” and that human activity “contributes” to the phenomenon. In that group were a number of Republicans facing voters in 2016, including Ayotte, Kirk, Portman, Murkowski and Sens. John McCain of Arizona and Rand Paul of Kentucky — along with Toomey.

The Pennsylvania Republican, who narrowly won his first term in 2010 on the strength of his staunch conservative fiscal record, isn’t a recent convert on the science of global warming, his spokeswoman said.

“Sen. Toomey has always said that human activity contributes to climate change,” said his spokeswoman, Elizabeth Anderson. “The degree to which we play a role is clearly up for debate.”