>Format</h2>
    <p>A data.frame with 173 observations on 10 variables:</p><ul><li><p><strong>state:</strong> state postal code</p></li>
<li><p><strong>district:</strong> congressional district</p></li>
<li><p><strong>democA:</strong> =1 if A is democrat</p></li>
<li><p><strong>voteA:</strong> percent vote for A</p></li>
<li><p><strong>expendA:</strong> camp. expends. by A, $1000s</p></li>
<li><p><strong>expendB:</strong> camp. expends. by B, $1000s</p></li>
<li><p><strong>prtystrA:</strong> percent vote fo