In February, Sen. Edward Kennedy, D-Mass., suffering from brain cancer, rallied to return to the Senate and cast a decisive vote to help clear the way for President Obama's $787 billion stimulus package.

But the elder Kennedy may not be the only family member capable of legislative drama.

On Friday evening it appeared his son, Rep. Patrick Kennedy, D-R.I., was poised to follow in his father's footsteps by helping House Democrats approve a major climate change and energy bill that teetered on the brink of failure.

House Democrats struggled for days to try to cobble together enough votes to approve the controversial legislation. House Majority Whip Jim Clyburn, D-S.C., conceded Friday that he wasn't sure if he had the votes to pass the bill. But late Friday afternoon, Kennedy appeared in the House chamber after being sidelined for weeks after checking himself into a rehabilitation center.

The Rhode Island lawmaker has fought battles with drugs and alcohol for years. In 2006, he slammed his car into a barrier near the capitol. He checked into a substance abuse center after blaming that incident on a mix of prescription drugs.

A Kennedy absence in the House was thought to cancel out the Republican absence by Rep. John Sullivan R-Okla. 

Sullivan recently requested a leave from the House for the month of June to seek treatment for an alcohol addiction. Kennedy supports the legislation and Sullivan does not. A Kennedy yea vote could mean the difference on the package.