More than half of those surveyed – 54 percent – have an unfavorable view of the GOP.
The numbers are far better for Democrats. Fifty-three percent say they have a favorable opinion of the Democratic Party, while 41 percent have a negative opinion about the party.
Both parties have lost some ground since February, according to the poll, with the Democrats' favorable rating down five points and Republicans' favorable rating down three points.
Congress, meanwhile, continues to be unpopular with a clear majority of Americans. Sixty-nine percent disapprove of the legislative body's performance, while just 29 percent approve.
Asked specifically about the performance of Democratic leaders in Congress, the results are somewhat more positive, though not much. Fifty-nine percent disapprove of their performance, while 38 percent approve. In April, 43 percent approved of Democratic Congressional leaders' performance.
Congressional Republican leaders, meanwhile, have the approval of just 33 percent of Americans, while nearly two in three disapprove of their performance.
Though Republicans are less popular than Democrats, the negative perception of Congress could hurt the Democratic Party in next year's midterm elections, since Democrats control both the House and Senate.
An unpopular Congress "will give Republicans a message to use against those Democrats," Stuart Rothenberg, editor and publisher of the non-partisan Rothenberg Political Report, told CNN.