Senate Minority Leader Mitch McConnellAddison (Mitch) Mitchell McConnellWarren on family separation policy: Trump is ‘taking America to a dark and ugly place’ Senate GOP tries to defuse Trump border crisis Schumer rejects GOP proposal to address border crisis MORE (R-Ky.) blamed moderate Democrats for the lack of a vote on building the Keystone XL pipeline.

Earlier this year, Senate Majority Leader Harry Reid (D-Nev.) offered to hold a vote on Keystone in exchange for passage of an energy efficiency bill. Vulnerable senators up for reelection this year, such as Sen. Mary Landrieu (D-La.) pushed for the vote. But it ultimately never happened because of the larger disagreement over amendments.

McConnell said that the Senate should at least have a non-binding vote on building the pipeline.

"When it comes right down to it, they haven’t even been able to secure a serious, gimmick-free floor vote from the majority leader to approve the Keystone pipeline. That should be the bare minimum here," McConnell said.

McConnell said the lack of a Keystone vote was due to Democrats catering to the most liberal base.

"The Senate Democrat leadership is obstructing construction of the Keystone Pipeline for one main reason – to please their patrons on the far left. And let’s be clear about something: the only reason they’re able to get away with it is because so-called ‘moderate’ Democrats let them — the same so-called ‘moderates’ who claim to have so much influence around here," McConnell said.

The Kentucky Republican accused moderate Senate Democrats of hypocrisy on the issue.

"The bottom line here is that these so-called ‘moderates’ can’t have it both ways. They can’t credibly claim to have influence on issues like these even as they let their party leaders shoot down almost every effort to achieve the things they claim to want, like Keystone," McConnell said.