Clinton defeated Bernie Sanders, getting 64.3 percent of the vote in the two-way race, with Sanders polling 35.2 percent.
Trump won a tight Republican race with 34.8 percent of the vote, with Marco Rubio coming in second with 32.0 percent of the vote. Ted Cruz was a distant third at 16.7 percent, and John Kasich was fourth at 9.7 percent.
It was a big, but not ultimately determinative, night for the two front-runners. Clinton picked up convincing wins in Alabama, Arkansas, Georgia, Tennessee and Texas, with Sanders winning in Oklahoma and his home state, Vermont, and leading in Colorado and Minnesota.
Clinton had a narrow lead late Tuesday in Massachusetts.
In the GOP voting, Trump won Alabama, Arkansas, Georgia, Massachusetts, Tennessee and Vermont, with Cruz winning his home state, Texas, and Oklahoma, and Rubio leading in Minnesota, with Cruz in second and Trump a distant third.