By Richard Cowan WASHINGTON, Dec 15 (Reuters) - U.S. Sen. Tim Johnson continued to improve after brain surgery this week, heartening fellow Democrats who were optimistic on Friday that he will be able to remain in the Senate. "Things certainly seem to be moving in the right direction," said Julianne Fisher, a spokeswoman for the 59-year-old senator from South Dakota. Johnson's emergency hospitalization on Wednesday for a serious illness raised concerns on Capitol Hill about his ability to continue in the Senate when the 110th Congress convenes on Jan. 4 -- as well as Democrats' chances of taking control of the Senate. The Democrats narrowly won an advantage in the Senate in November elections. But if Johnson has to leave the Senate, South Dakota Gov. Michael Rounds likely would appoint a fellow Republican to fill the last two years of Johnson's term. That could give Republicans control of an evenly split Senate since Republican Vice President Dick Cheney can cast tie-breaking votes. Former South Dakota Sen. Thomas Daschle, who led Senate Democrats for several years before his 2004 defeat, visited Johnson on Friday. Daschle told reporters Johnson was "doing quite well" and gave an upbeat assessment of his future. "I fully expect him to be back in the saddle and working and voting and conducting his public life," Daschle said. Johnson, who will turn 60 on Dec. 28, was taken to George Washington University Hospital on Wednesday and had brain surgery to stop dangerous bleeding that caused speech problems earlier that day. Doctors have not ruled out the possibility of additional surgery. But they said on Thursday that he so far had experienced an "uncomplicated" recovery from the operation to deal with a brain malformation that he probably had since birth. President George W. Bush's press secretary, Tony Snow, said no one from the White House had contacted Rounds about the situation. "This is a time to pray for Tim Johnson's health," snow said. "And I'll leave it to others to start doing political calculations." In elections last month, Democrats wrested control of the U.S. House of Representatives and Senate from Republicans, promising to challenge Bush's agenda in the last two years of his presidency. When the Senate convenes in January, Republicans and Democrats will have to agree on rules for running committees and other functions of the 100-member chamber in case of a change in the political makeup resulting in a 50-50 split. In a statement released on Thursday, Johnson's wife, Barbara, said her husband was responding to her voice and following directions and that he had reached for her and held her hand. (additional reporting by Susan Cornwell)
