Last night, the parlour room talk was the same all over. With a month until election day, is Mr Perot a tiresome distraction who lost all credibility when he drew back from the race in mid-July, letting down millions of supporters? Or is he a multi-billionaire force still to be reckoned with?
Mr Clinton, who seems recently almost to have been drifting towards victory, apparently has the most to lose. He said as much before the Dallas announcement, warning that a Perot candidacy could split the anti-Bush votes on 3 November and hand the White House back to the President.
Mr Clinton insisted, however, that he would not be changing tactics to take account of Mr Perot's entry. 'I am going to run my race. I am going to engage Mr Bush. We need to change the incumbent of the White House desperately', the Arkansas Governor said in a television interview.
A former Bush Cabinet member, Willian Bennett, meanwhile, dismissed the Texan as an 'egotistical pest'.
Predicting what the Perot candidacy will bring is hard for several reasons. He has almost limitless private resources to drawn on for advertising. More critically, he is free to decide where most to target his campaigning. If, as is widely reported, his main argument is with President Bush, he may seek to weaken the President in southern states, like Texas. That could only help Mr Clinton.
A CNN poll released immediately after Mr Perot's announcement suggests strongly that the Democrat should relax. It showed that in a three-way race, Mr Clinton's lead would actually grow to 17 points, giving him 52 per cent compared with 35 per cent for Mr Bush and just 7 per cent for Mr Perot. The same poll showed Americans disapproving by almost two to one of Mr Perot deciding to leap in so late in the game.
Never before in US political history has an independent announced so close to polling day. Although Mr Perot ran a shadow campaign before stepping back in July, he never then actually declared. At its peak, Mr Perot's popularity gave him a lead of 36 per cent in one poll over 30 per cent for Mr Bush and 26 per cent for Mr Clinton.
Clinton advisors were negotiating in Washington yesterday with Bush campaign chiefs to resolve the format and timings of presidential television debates. A compromise is expected between the proposals of a bi-partisan commission, backed by Mr Clinton, for three debates chaired by a single moderator, and Mr Bush's belated counter offer for four debates, two with a moderator and two with a panel of journalists - his preferred format.
Officials from both sides concede that the debates would probably become a three-way affair, with Mr Perot included. They said the Texan would have to accept any format agreed by the two sides.