Don Young, Alaska's sole representative in the House, was elected to a 21st term. With about 86 percent of precincts reporting, he had about 64 percent of the vote, while his main opponent, Democrat state Rep. Sharon Cissna, had 28 percent.
Libertarian candidate Jim McDermott received 5 percent of the vote and unaffiliated Ted Gianoutsos got just under 2 percent.
Romney got the state's overwhelming nod for president, 55 percent, to President Obama's 40 percent.
Voters also made decisive changes to the state Senate, putting Republicans into 13 of the chamber's 20 seats, the Anchorage Daily News reported.
For the last four years, Republicans and Democrats had split the Senate 10-10.
Four Democratic members of the Senate's bipartisan coalition were defeated, while two Republican members of the coalition lost in the August primaries.
With most votes tallied, the results in House races were not as definitive, but Republicans appeared to have the edge in more than half of the 26 contested races.
All 40 state House members were up for re-election, but 10 Republicans and four Democrats ran unopposed. The Republicans, with 22 members, are in the majority.
Three quarters of the state House districts have more registered Republican voters than Democratic.