Senate Republicans on Thursday unanimously promoted Sen. John Thune (S.D.) to chairman of the Republican Policy Committee and elected Sen. Lisa Murkowski (Alaska) as vice chairwoman of the Senate Republican Conference.

The Conference’s special election was held after Sen. John Ensign (Nev.) resigned as policy chairman after admitting to an affair with a former campaign staffer. Ensign acknowledged the relationship on June 16 and resigned his No. 4 leadership job the next day.

Thune has long been seen as one of the GOP’s brightest stars following his historic defeat of former Senate Minority Leader Tom Daschle (D) in the 2004 election. Former Minority Whip Trent Lott (R-Miss.) took Thune under his wing, and the South Dakotan quickly became one of his most-trusted lieutenants in the Senate.

Murkowski, who has served this year as counselor to Minority Leader Mitch McConnell (R-Ky.), has also enjoyed a quick rise in the ranks.

Up for re-election in 2010, Murkowski was first appointed to the Senate by her father, former Alaska Gov. Frank Murkowski (R), to fill out the remainder of his Senate term. Murkowski had been dogged by charges of nepotism and faced a difficult election in 2004.

But since then, she has solidified her position both at home and in the Senate and has become one of the Conference’s leading voices on energy issues.