The most telltale clue to Congress's fall agenda may be an item that still may be added: middle-class tax cuts. Down in polls and divided internally, Republicans want to block debate on domestic policy and shift attention to national-security issues that command more party unity. But census data last week highlighted the economic squeeze on many families, and House leaders are considering a pre-election bid to make permanent the $1,000 child tax credit and marriage penalty relief provisions enacted in 2001. Like most of the Bush administration's tax breaks, these are due to expire at the end of 2010, when...