After expanding to its widest in years last month, the gap between GOP and Democratic voter enthusiasm is shrinking:

PRINCETON, NJ — Republican registered voters’ enthusiasm about voting in this year’s midterm elections has declined significantly in recent weeks. As a result, Republicans’ advantage over Democrats on this measure has shrunk from 19 points in early April to 10 points in the latest weekly aggregate.
In late March and early April, after Congress’ passage of healthcare reform, both Republican and Democratic registered voters became more enthusiastic about voting in this year’s elections. Republicans’ enthusiasm peaked at 54% “very enthusiastic” in late March and early April, but is 43% in the latest weekly update, from April 27-May 2 — essentially where it was before healthcare passed. By contrast, Democrats have more or less retained the slightly higher level of enthusiasm they showed right after the healthcare bill milestone.
Republicans’ current 10-point lead is the smallest Gallup has measured since it began tracking 2010 election attitudes in March.

Come on, people. It’s a long way until November.