Lobbying the House
Lobbyists will focus on the House
For money Bill- to defund projects or add pork to bills.
To initiate an in investigation- the House is more partisan and will be more open to making trouble if they are controlled by the party which opposed the president. 2015 the House conduced lengthy hearings in to the attack on the US Embassy in Benghazi- mostly to embarrass Hilary Clinton. Calls to impeach Obama were common in the House. The House immediately impeached Trump after the mob attack on Congress.
House members are more receptive to shifts in popular opinion - they face election every two years. Therefore more vulnerable to lobbying which targets their constituents- (However, with so few competitive seats this is less true of recent years Although this opens them to more partisan lobbying e,g the NRA will lobby to oppose gun control measures even when these have wide public support because they know members of the house only need to appeal to a narrow base of opinion.
As the House was given the exclusive power to initiate money bills, this makes it a significant target for groups wishing to secure a slice of the colossal annual federal budget, or those wishing to influence where that money is spent. In this way since the Republican Party gained control of the House following the 2010 'Tea Party tidal wave', the House has voted on 37 separate occasions to repeal 'Obamacare', with the most recent vote seeing all Republicans and just two Democrats support the measure. Certainly, the on-going budget negotiations of 2013 show the influence of conservative groups on the House, with many Tea Party Republicans making clear their willingness to block any budget which raises taxes or provides funds for 'Obamacare', raising the threat of a government shutdown in the USA.