\begin{table}[htbp] 
\centering 
\caption{\bf NP-Scores of State Legislators, by Party (Threshold to Define Pools = 50 Percent)} 
\label{tbl_summary_stats_50} 
\begin{tabular}{lccrccr} 
\toprule\toprule 
& \multicolumn{3}{c}{Democrats} & \multicolumn{3}{c}{~Republicans} \\ [.05in] 
            & Mean       & Median     &           & ~Mean       & Median     &           \\ 
Item        & NP-Score   & NP-Score   & \# Legs.  & ~NP-Score   & NP-Score   & \# Legs.  \\ [.01in] 
\midrule 
National Average/Median     & -0.77 & -0.78 & 34,682 & ~0.74 & 0.75 & 35,696 \\ [.01in] 
\midrule 
            &    &    & \# Pools  &    &    & \# Pools  \\ [.01in] 
\midrule 
All Pools                   & -0.85 & -0.86 &  3,665 & ~0.73 & 0.77 &  3,428 \\ [.01in] 
Pools in Safe Districts     & -1.16 & -1.10 &  1,462 & ~0.91 & 0.89 &  1,678 \\ [.01in] 
Pools in Competitive Dists  & -0.83 & -0.86 &    957 & ~0.61 & 0.67 &  1,016 \\ [.01in] 
Pools With 1+ Cong Cand     & -0.89 & -0.93 &    239 & ~0.77 & 0.77 &    320 \\ [.01in] 
Pools With 0 Cong Cands     & -0.85 & -0.85 &  3,426 & ~0.73 & 0.77 &  3,108 \\ [.01in] 
\midrule 
National Std. Dev.          & 0.50 & &  & ~0.38 & &  \\ [.01in] 
Avg. Within-State Std. Dev. & 0.32 & &  & ~0.28 & &  \\ [.01in] 
Avg. Within-Pool Std. Dev.  & 0.26 & &  & ~0.24 & &  \\ [.01in] 
\bottomrule 
\multicolumn{7}{p{.9\textwidth}}{In the first row the unit of observation is the individual legislator.  In rows 2-6 the unit of observation is the pool.}
\end{tabular} 
\end{table} 
