Business as usual in Washington America seems to be getting used to massacres. On Monday, when a gunman went on a killing spree that claimed 12 innocent lives at the Navy Yard in Washington, I was about two miles away at a conference in a smart hotel. Both guests and staff seemed largely unfazed by the nearby mayhem. In the hotel gym, businesspeople ran on their treadmills, half-watching the horrors unfold on CNN. At the front desk, the "have a nice days" were issued with the usual bright smiles. I wondered whether the atmosphere outside might be more tense, particularly given initial television reports that a shooter was still on the loose. Perhaps Washington would be subjected to the kind of lockdown imposed after the bombing of the Boston marathon in April? This was a particular worry for me since I had to walk across town to a meeting at the Eisenhower Executive Office building, which adjoins the White House. In the event, however, the atmosphere in the streets was strikingly normal. Tourists continued to wander up and down the Mall. A few of the streets around the White House were taped off. But alternative routes were suggested and official meetings were continuing. For better or worse, it was business as usual. Perhaps because gun massacres are a fairly regular occurrence, almost nobody expects that the latest one will make it any easier to pass new gun control laws. Barack Obama tried and failed to get something through Congress following last year's killings at Sandy Hook Elementary School in Connecticut. Indeed, these days the president seems to find it almost impossible to get anything through Congress. Capitol Hill is gearing up for yet another stand-off over the budget, with the prospect of a government shutdown at the start of October. No matter that a previous showdown over the debt ceiling led to a credit downgrade for the US. This week, Mr Obama also had to accept that Larry Summers, his favoured candidate for president of the US Federal Reserve, would not be confirmed by Congress. And it is only the Russian diplomatic initiative on chemical weapons that gave him the breathing space he needed to postpone indefinitely a congressional vote on missile strikes on Syria, which was almost certainly heading for defeat. Losing the vote would have been a hammer blow to Mr Obama's presidency and a historic setback for presidential power in the making of foreign policy. Jacob Heilbrunn, the new editor of the mildly conservative National Interest magazine, told me he reckoned a lost Syria vote would have been the biggest setback for presidential power in the making of foreign policy since Woodrow Wilson failed to persuade Congress to let the US join the League of Nations. That may be going it a bit. But there is no doubt Mr Obama owes a huge debt of gratitude to President Vladimir Putin. The Russians doubtless had their own motives for their chemical weapons proposal. But it comes to something when Mr Obama has more cause to be grateful to the Kremlin than to Congress. For political obsessives in Washington, however, the business of governing is a pale substitute for the real fun - which is campaigning for office. Mr Obama was sworn in for a second term only a few months ago, but the papers here are already full of speculation about the runners and riders for 2016. The fact that Joe Biden has just paid a visit to Iowa - the first state to vote in the primary and caucus season - has provoked plenty of coverage, even though the vice-president is already 70, and most of the Democratic party establishment is lining up behind Hillary Clinton (66, since you ask). Meanwhile, interesting things are happening on the Republican side. Party discipline in Congress has all but broken down. Although John Boehner, the speaker of the House of Representatives, was prepared to vote for strikes on Syria, his colleagues were massively against. Sarah Palin's tweet about Syria - "Let Allah sort it out" - captured the rise of an anti-interventionist (some say isolationist) strain in the party. But who could be the candidate to capitalise on this? Ms Palin seems to be out of the running. Instead, the coming man is Senator Rand Paul of Kentucky, a younger, slightly less quirky version of his father, Ron, who beat the drum for the "come home America" crowd in the past two presidential elections. But embracing Paulism would mean that Republicans abandoned their historic claim to be the party of national security and the military. And that is probably still a bridge too far.