Sen. John Cornyn, R-Texas. (AP Photo via DayLife)

—  The leader of the group tasked with electing Republicans to the U.S. Senate told the Wall Street Journal this weekend that there may be a weak link in the field vying to replace Democratic U.S. Sen. Claire McCaskill.

Sen. John Cornyn, chairman of the National Republican Senatorial Committee, voiced his apparent unease with one of the three contenders in the WSJ’s “Weekend Interview” series.

“We have a three-way primary, and it really depends on who’s nominated, whether they are able to withstand what they know is coming at them in a general election,” Cornyn said, according to the WSJ.

Nonetheless, Cornyn asserted McCaskill is “very vulnerable.”

According to the most recent polling, State Treasurer Sarah Steelman polls highest against McCaskill, followed by U.S. Rep. Todd Akin (No public poll has yet included St. Louis businessman John Brunner). But Steelman has had challenges raising campaign funds and has faced unease in conservative voters.

Akin holds strong support from conservatives, but many Republicans question whether his support goes beyond that.

A spokesman for the NRSC was not immediately responsive to a request for clarification of Cornyn’s statement.

Republicans will defend only 10 seats next year, allowing the NRSC to play heavily in nearly a dozen states, including Missouri, in their hope to take back the Senate majority.