A group of Senate Democrats is urging President Obama to approve the Keystone XL pipeline by the end of next month, saying the process “has already taken much longer than anyone can reasonably justify.”

The letter, spearheaded by Sen. Mary Landrieu (D-La.), who faces a tough reelection bid this year, requests that Obama set a hard deadline for Secretary of State John Kerry to make his national interest determination. [READ THE LETTER.]

The senators also press Obama to set a timeline for himself and to make a final decision on the pipeline by May 31.That deadline would give Obama a few weeks to decide the fate of Keystone, which would carry crude oil from Alberta to Gulf refineries.Right now, the State Department is winding down its interagency review, which is expected to wrap up in early May. Kerry would then need to make his recommendation to Obama, leaving the rest to him.

But, here’s what he’s also hearing: