BOSTON (CBS) – A pair of senators from Massachusetts lashed out against the Republicans’ tax reform legislation, which narrowly passed early Saturday morning.

The bill, which was approved by a 51-49 margin with no Democratic support, was voted on just before 2 a.m.

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President Donald Trump tweeted about the vote on Saturday.

Massachusetts senators Elizabeth Warren and Ed Markey expressed frustration with the bill.

Many Democrats expressed frustration that the full text of the bill was sent out just hours before the vote. It also included amendments written in the margins.

Warren called the bill “another punch in the gut” in a string of tweets after the vote.

In Boston on Saturday, the vote drew protestors who criticized the tax plan outside the Apple Store on Boylston Street.

The bill will now will head to conference, where House and Senate negotiators will work out differences.

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Tennessee Republican Bob Corker was the only one in his party who voted against the legislation.