“The point I would make is that [Obama] needs to sell not only the leadership but also the rank-and-file members in both houses to get the votes,” Cornyn told reporters after a White House meeting on Tuesday. “But even more importantly than that — that he needs to sell it to the American people. My constituents that I’ve talked to are deeply skeptical of the plan and actually don’t really understand what the strategy is. I think [Obama] needs to make that case more broadly.”

Indeed, with Obama and Reid facing a 60-vote threshold to overcome an expected filibuster once the Syria resolution reaches the Senate floor next week, the vote is still too close to call. Top Democrats believe they will need ten to 12 Republicans to back the measure to get it across the finish line, and so far, the tally is very close.

Out of 46 Senate Republicans, there are roughly eight to 10 expected “yes” votes at this moment, including Sens. Bob Corker (R-Tenn.) and John McCain (R-Ariz.), according to Senate aides and public tallies of the vote. Corker, the ranking member on the Senate Foreign Relations Committee, is negotiating with Reid and Sen. Bob Menendez (D-N.J.) over a more narrow use-of-force resolution than the one initially proposed by the White House. One of McConnell’s aides is monitoring the talks, sources say.

Another 15 Republicans are seen as “no” or “leaning no,” not including Cornyn. The remaining 20 or so are undecideds.