No: there is no legal mechanism for the president to suspend an election, nor is there a precedent, as elections were held in 1864 during the Civil War, 1944 during World War II, 1968 and 1972 during Vietnam, and during Iraq in 2004. Democratic institutions in the United States are far too secure for this type of scenario to happen.
If you're asking what the effect of a strike on Iran would be, it's hard to say. There could be a rallying around the flag, or the people could say enough is enough and turn on McCain and other Republicans at the polls.
In terms of what form military action will take, it will most likely involve air strikes, as the army is too heavily committed to Iraq and Afghanistan to invade Iran.
Yeah. You're pretty much right, except for the last thing you said. I think McCain could get a chance for a war with Iran by as early as 2010-2011. The idea that I thought of would be that Petreus would begin withdrawing the soldiers from Iraq in September after declaring victory. This declaration of victory could give McCain the 10 point late-campaign bounce that propelled the GOP to victory in 1988, 2000 and 2004, if their high-tech lynching of Obama fails or back fires and could turn a small Obama landslide into a comfortable 2004-esque McCain victory, and a 40,45 state landslide for McCain if the lynching works. After than, McCain can preside over removing half of the troops from Iraq whilst leaving about 6 or 7 brigades there. At that point, he should be able to call the reserve, and have about 25 or 30 brigades ready to invade Iran by mid-term. If there is no major change in the Middle East by the Mid-Terms, and if he does well in the mid-terms, he will invade Iran under a mandate that is provided by a weakened Democratic, if not Republican congress. If there is another terrorist attack, or if Iran explodes a Nuclear Weapon before the 2010 elections, we will probably invade before the mid-terms and the country will rally behind the flag and throw the fledgling Democratic Majority out to give McCain the mandate he needs to continues the wars. However, if McCain and Peterus are dead set on occupying Iraq, and nothing happens, I think McCain, if he wins by lynching Obama, like Dukakis and Kerry were lynched, will probably not even touch Iran because airstrikes would be pretty useless and would most certainly backfire. Iran's nuclear capabilities would go relatively unharmed and there would be a new Embargo that would push gas prices to around 6-10 dollars a gallon.
Long story short- We either attack Iran or we don't....and we will only attack Iran if the Republicans are in power in 2010.