The 2000 presidential election was a big driver. No one wanted to spend November of an election year hearing about "chads" ever again, so the Help America Vote

The 2000 presidential election was a big driver. No one wanted to spend November of an election year hearing about "chads" ever again, so the Help America Vote Act was passed. Among other things it provided federal funding for states to replace problematic punch-card voting machines. Electronic voting, in theory, could be easier to use than a paper ballot and can automatically check that the ballot is filled out correctly (e.g. not voting for multiple candidates for a single office). And of course there were companies lining up to help states spend those federal dollars on overpriced touchscreen PCs running Windows XP.