To answer this question it is firstly necessary to break down what the functions of Congress are, as well as what determines whether something is 'effective'. Normally the best way to break down the functions of Congress is through the acronym 'LRO' - legislation, representation and oversight. I would as a result split my essay into 3 paragraphs, each tackling one of the three main functions of Congress and determining how successful it is in completing its purpose.
Looking at legislation, due a lack of bipartisanship as well as the bicameral structure of the Senate and the House I would argue that Congress does not carry out its legislative functions effectively, with gridlock often occurring as a result. In terms of representation, with Congress lacking numbers in terms of gender and ethnicity that proportionately matches the population, once again it is difficult to claim that Congress fulfils this function either despite recent improvements. In terms of oversight, whilst Congress can have great influence upon the executive this is largely reliant on the majority in Congress being opposite to the executive, and can often as a result infringe on the duty of passing legislation. As a result, I would conclude that Congress struggles to a large degree to carry out its functions in any effective manner.