Dakota, Idaho and Alaska rounded out the calendar.
Some 419 delegates were at stake in the 10 states.
Romney picked up at least 129 delegates during the evening, Santorum
47, Gingrich 42 and Paul at least 10.
That gave the former Massachusetts governor 332, more than all his
rivals combined, including endorsements from members of the Republican
National Committee who automatically attend the convention and can
support any candidate they choose. Santorum had 139 delegates,
Gingrich 75 and Paul 35. It takes 1,144 delegates to win the
nomination at the Republican National Convention in Tampa, Fla., this
In interviews as voters left their polling places, Republicans in
state after state said the economy was the top issue and an ability to
defeat Obama was what mattered most as they made their Super Tuesday
They also indicated nagging concerns about the candidate they
supported, even in Massachusetts, There, one-third of all primary
voters said they had reservations, and about three-quarters of those
voted for Romney.
Massachusetts is a reliably Democratic state in most presidential
elections, but in Ohio, 41 percent of primary voters said they, too,
had reservations about the candidate they supported. No Republican has
ever won the White House without capturing Ohio.
Gingrich's victory was his first since he captured the South Carolina
primary on Jan. 21, and the former House speaker said it would propel
him on yet another comeback in a race where he has faded badly over
the past six weeks.