There will be a generational shift in the House after Tuesday's elections. Republicans who have less than three years of experience in the House -- many of whom are Tea Party members -- will make up more than a third of the House GOP. This means conservatives will have more influence in Congress regardless of who wins Tuesday's election.
According to Charlie Cook of the "Cook Political Report":
While the GOP will retain a strong majority, there will be historic generational turnover. More than four fifths of the 87 member GOP freshman class are likely to win a second term, but 62 seats have no incumbent on the ballot (a record since 1992), and the next freshman class is likely to include between 75 and 85 members. It’s certain that more than a third of members will have less than three years of House experience when the next Congress is sworn in in January.
Cook also writes as the Tea Party is expected to make more gains, continuing the momentum from the historic midterm elections in which they gave Republicans the majority back in the House, "Democrats in the Blue Dog Coalition are likely to be cut in half for the second consecutive cycle."
On the other hand, "women and minorities will be a majority of the Democratic caucus," and Democrats in the House are likely to move even more to the left.