(CNN) - The candidate will now become the incumbent.
As expected, Nevada Gov. Brian Sandoval Wednesday appointed Rep. Dean Heller, a fellow Republican, to replace Sen. John Ensign, who is resigning early next month. The move makes Heller the sitting senator for a seat that's up for grabs next year.
Ensign, who is under an ethics investigation by the Senate, announced last week that he will resign his seat on May 3. The two-term Republican senator earlier this year said he would not run for re-election in 2012 following revelations that he had an affair with a female aide who was the wife of another top aide and his parents subsequently gave money to the aides' family.
Heller, who had been considering a primary challenge to Ensign, announced that he would run for the open seat in 2012, quickly becoming the consensus candidate for national Republicans.
"Dean is an experienced representative who is ready for the responsibilities of this office, and who will work hard, not just for Nevada, but for the entire nation," said Sandoval in a statement.
In what could be seen as a veiled slight to Ensign, Sandoval also praised Heller as "a compassionate man of deep personal integrity."
Democrats are targeting Nevada in next year's election, seeing the state as a possible pick up. But with the scandal- plagued Ensign out of the picture and Heller soon to be sitting in the seat, Republicans may be relieved.
Sen. John Cornyn, the chairman of the National Republican Senatorial Committee, quickly congratulated Heller, who's represented Nevada's second congressional district for three terms.
"Dean's Democratic opponents have embraced Harry Reid's failed, big government policies, and if elected they will continue to steer our country on a downward path of fewer jobs, more spending and a record debt," said Cornyn in a statement. "Next year's election is critical, and in the months ahead, voters throughout Nevada will see firsthand why Dean Heller is the right leader, at the right time, to continue serving them in the U.S. Senate."
The Democratic Senatorial Campaign Committee says Heller's appointment to the Senate will now put him increasingly in the spotlight.
"As an un-elected senator, Dean Heller will now be forced to explain to all Nevadans why he is working in Washington to end Medicare and cut loans for small business that create jobs in Nevada," says DSCC communications director Matt Canter. "Becoming the un-elected senator will come with a level of heightened scrutiny that will hurt Heller in a general election."
The DSCC earlier this month endorsed Rep. Shelley Berkley, a seven-term congresswoman who represents the state's first congressional district. She raised nearly $700,000 in the first three months of this year, with nearly $1.6 million in the bank. That's slightly more than $1.4 million that Heller had in the bank as of April 1.
But Berkley could face a primary opponent in self-funding Democratic lawyer Byron Georgiou, who's also in the race. He announced his Senate run in early March, and reported raising $1.1 million in the first quarter of this year, which includes $500,000 of his own money.
Heller's move to the Senate now opens up his seat in the House.
Sandoval announced that details on a special election would come soon, saying, "I pledge to work closely with Secretary of State Ross Miller on the timing of the upcoming transition and resulting special election. I have asked Secretary Miller to provide me with information on the rules for conducting this election at his earliest convenience."
CNN's Rebecca Stewart contributed to this report.