Public approval for Congress dips into the single digits. I'm not surprised for the reason often given--people (especially in gerrymandered districts) like their own crook--and distrust all the others. Hence, a better measure of how people will vote would be reflected in, e.g., whether they think Obamacare should be repealed.
But I also raise the question whether the members of Congress would give any higher rating of their own institution. Somehow I doubt it. The separation of powers and the bicameral Congress create such frustrations. But there is only one President.