\begin{table}[htbp] 
\centering 
\caption{\bf Within-Pool Comparisons: Predicting Probability of Running from Ideology} 
\label{tbl_appendix_lpm_run_33} 
\begin{tabular}{lcccccc} 
\toprule\toprule 
& \multicolumn{3}{c}{Democrats} & \multicolumn{3}{c}{~Republicans} \\ [.05in] 
Sample                 & Coeff.  & Std. Error  &  \# Obs.  & ~~Coeff.  &  Std. Error  &  \# Obs.  \\ [.01in] 
\midrule 
All pools              & -0.006 & (0.015) & [3898] & ~~0.063 & (0.016) & [5993] \\ [.01in] 
Open seats             & 0.015 & (0.019) & [2104] & ~~0.077 & (0.019) & [3001] \\ [.01in] 
Safe districts         & -0.019 & (0.024) & [1566] & ~~0.071 & (0.026) & [2910] \\ [.01in] 
Competitive districts  & 0.020 & (0.021) & [1527] & ~~0.062 & (0.022) & [2720] \\ [.01in] 
\bottomrule 
\end{tabular} 
\end{table} 
