His suit jackets were too big back then. His hair wasn’t as carefully trimmed. His ties had more patterns than the solid red or blue he deploys almost daily as president.

But cosmetics aside, President Obama, who will have his first one-on-one session with Mitt Romney on Wednesday, speaks and debates in a remarkably similar way to when he first arrived on the national scene in 2004. Obama’s careful mid-sentence pauses, professorial asides that include detailed references to history and data, and style of highlighting agreements with his opponents, then shifting to differences, remains consistent from his encounters with Illinois Republican Alan Keyes back in 2004, then Hillary Clinton and John McCain in 2008, and now when he faces tough questioning during interviews.

(Here’s the full video of the first of the three 2004 debates between Keyes and Obama.)

The president is known for his soaring, optimistic rhetoric, but that largely comes from his speeches. By their nature of specific questions and a contest between candidates, debates require Obama to show different characteristics: sarcasm, combativeness, even indignation.

“While I was working on those streets, watching those folks see their jobs shipped overseas, you were a corporate lawyer sitting on the board of Wal-Mart,” Obama told Clinton in a January 2008 debate, after his rival at the time suggested he had spoken favorably of Ronald Reagan’s economic policies in the 1990′s.

Obama’s style is not likely to shift. Like in 2004 and 2008, the president will face an opponent who is trailing and looking to alter a race in which Obama is the favorite. Obama, like in the past, won’t be looking to level new shots as much as he is playing defense.

And while his aides are urging the president to keep his answers short, that too is unlikely to happen. Obama’s answers became crisper from 2004 to the 2008 primaries and then he again improved in his brevity when facing McCain. But at the core, he likes to fill his answers with context and detail, not only explaining his policy but how he arrived at it.

The series of one-on-one debates in 2008 against Clinton during the Democratic primary, after all of the other candidates dropped out, are perhaps the best model for what will happen over the next month. Romney, like Clinton, is an experienced debater who thrived in a series of multi-candidate sessions during the primaries. Romney is likely to interrupt Obama frequently during the debates, as Clinton did.