The three biggest ticking timebombs
1. The US Internal Revenue Service this week admitted to targeting conservative groups for tax investigations – especially those with "Tea Party" in their names – before the 2012 election. The White House press secretary later admitted these actions were "inappropriate", although that seems a rather kind way of describing the politicisation of bureaucracy. George F Will, one of America's leading political commentators, has said that he sees "echoes of Watergate" in it all.
2. The second scandal relates to the deaths of four Americans, including the US ambassador to Libya, last September. Mr Obama faced awkward questions about it at the last election, but now that emails have been released showing a dispute between the State Department and the CIA over the tragedy, they are more pressing than ever.
3. The seizure of phone records of senior journalists at the Associated Press news agency in a leak investigation.