Sen. Kay Bailey Hutchison (R-Texas) now appears likely to stay in the Senate even as she runs for governor, counter to what was originally expected when she began preparing to seek her state’s top post last year.

Republican sources in Washington, D.C., on Monday predicted that the Texas Republican will continue to serve in the Senate, resigning only if she wins the Lone Star State governor’s mansion in November 2010. Hutchison had been expected to resign her Senate seat in the coming months to focus on her campaign full time.

Should Hutchison still decide to step down, she would likely do so at the end of this calendar year, setting up a May 2010 special election to fill out the remainder of her current term, which expires in 2012. Gov. Rick Perry (R) would presumably appoint someone to replace Hutchison in the interim, as state law empowers him to do.

“I think she won’t resign before the end of the year, if at all,— one Republican operative based in Washington said Monday afternoon.

Hutchison’s office declined to comment on the matter.

Texas remains solid Republican territory for statewide races, but some in the GOP have worried that the unpredictable voter turnout in a special election for a vacant Senate seat could allow the Democrats to flip Hutchison’s seat. Republican Senate leaders have communicated their concerns to Hutchison, according to GOP sources.

Hutchison is popular at home, and the only serious competition that she is expected to face in her run for governor — if any — is from Perry in the March 2010 GOP primary.

Perry, in his second full term, has indicated he intends to seek a third term next year. But some in Texas believe he is posturing to maintain some leverage with the Texas Legislature, and that he will ultimately step down upon the conclusion of his current term.

Some Republican operatives monitoring Hutchison’s movements believe she would be more inclined to resign her seat if Perry runs. But other GOP strategists believe a competitive primary from Perry would force her to remain in office.

“I think she wanted to resign early but realizes that with the Democrats standing on the doorstep, there is just no way she could do that. It would open her up to a huge point of attack that Perry could use in a GOP primary that she put her own political ambitions ahead of potentially handing the Democrats a filibuster-proof Senate majority,— said one Republican strategist.