Senate Democrats' campaign arm had another productive fundraising month, hauling in $7.7 million in July and topping its Republican counterpart.

The Democratic Senatorial Campaign Committee ended July with $32 million in its campaign account, it announced Tuesday. The National Republican Senatorial Committee ended the month with $26.6 million in the bank after bringing in nearly $5.5 million in July.

Republicans need to gain six seats to win back the Senate majority. Unlike the House, which is overwhelmingly unlikely to flip party control, control of the Senate is up in the air heading into the fall campaign.

The House and Senate Democratic campaign committees have put up impressive fundraising numbers this year thanks in large part to President Obama, who has regularly attended high-dollar events for the organizations. Obama took time out of his vacation on Martha's Vineyard last week to attend a DSCC fundraiser there.