I don't have enough data or understanding to comment much on what Clinton did, but my hazy prediction would be that he sat in office as the tech market (and bubble) exploded into life and boosted tax revenue. Of course, given my admitted ignorance on this subject, there's obviously a good chance that I'm completely wrong.
IMO there were really 5 pillars to the surpluses of the 1990’s.
The first was Bush 1 being forced to retreat on his “no new taxes” campaign pledge in the 1991 budget deal. Clinton doesn’t deserve much credit for this one, nor did the Republicans in congress who essentially threw Bush under the bus for what turned out to be a very good decision.
The Second was the pay-go principle which was largely coming from moderate democrats in Congress but was supported by Clinton.
The third was simply sound spending. For example Clinton refocused the US military to favor quality over quantity, and making effective use of existing weapons platforms instead of spending hundreds of billions developing new platform after new platform. Anyone who had the opportunity to see the quality of US forces in the first vs the second gulf war should be able to attest how much better the US military was in 2002 vs 1992 (a LOT) despite being smaller and less expensive.
The forth was to keep Greenspan as Fed chairman and he continued Paul Volker's approch to running the Fed. Clinton gets some credit here, but so does every President datign back to Carter who appointed Volker.
The final part, as you say was the tech boom, but that wasn’t something that happened on it’s own. The Clinton Administration, Al Gore in particular played a huge role in tech taking off like that.
he tech boom was driven by the growth of the internet, which is 1991 was a loosely connected academic network that couldn’t support business or public use. Basically the internet at this point was an ad-hoc assortment of T1 phone lines between universities, and while the protocols for e-mail, http, etc were in place none of the end user apps were.
Clinton/Gore drove the concept of “the information super highway”, which had two parts. The first was the development of tools aimed at the public, the major result being the Mosaic web browser which was developed under the sponsorship of the NCSA and who’s developer later developed Netscape. Both Internet Explorer and Firefox today descend directly from Mosaic.
The second part of the initiative was to replace the lose academic network with a public utility of the sort we have today. The US government created incentives for private business to build their own networks then create high speed connections between them and allow data to be transferred between them. This is basically how the internet works today, and it was this change that made it possible for companies like AOL to start large scale drives to build their own networks and get people on the internet.
