It's pegged as the Democrats vs. the gun lobby, but of course it's more complicated than that.

Today, at noon, the Senate is expected to take up an amendment by South Dakota Republican John Thune that would allow individuals with permits to carry concealed weapons to carry them across state lines — though only if the visited state laws allow conceal-and-carry permits.

It's part of the fiscal 2010 defense authorization bill, but don't ask me to explain the relevance of having the gun bill attached to it.

 

Dick Durbin, the Illinois Democrat who is the Senate majority whip, is trying to round up enough votes to stop the bill with a filibuster. But it's not just the National Rifle Association, or the Republicans, he is up against.

Senate Majority Leader Harry Reid is voting for the bill. Reid has a potential tough fight for re-election in Nevada next year, where polls show him with diminished approval ratings. Three other Western Democrats — Mark Begich of Alaska and Montana's Max Baucus & Jon Tester — are co-sponsoring the bill. And Greg Vadala of Congressional Quarterly points out that other Democrats may be on the fence.

If Durbin and other opponents of Thune's measure are to succeed, they'll need to pick up the votes of new Democratic senators who represent states where lawmakers are often loath to vote against the wishes of gun owners.

As of Tuesday afternoon, freshman Democratic Sens. Mark Udall and Michael Bennet, both of Colorado, and Mark Warner of Virginia said they were undecided.

"I think you really have to consider the states' rights question and whether the reciprocity that's already in place between a lot of states is really sufficient, or do you need to have this federal pre-emption," Udall said. "The two points of view are legitimate, so I'm taking my time."

In May, Reid, Bennet, Warner and Udall joined 23 fellow Senate Democrats in backing Oklahoma Republican Tom Coburn's amendment — to credit card legislation (PL 111-24) — allowing people to bring concealed and loaded guns into national parks.

And in February, Reid and the three freshmen joined 18 Senate Democrats to help adopt an amendment by John Ensign, R-Nev., that would roll back restrictions on gun ownership in the District of Columbia. It was attached to legislation (S 160) that would give the District full voting representation in the House, and the provision subsequently stalled House action on that bill.

Thune argues that people with concealed weapons permits, such as truckers, should be able to protect themselves when they cross state lines. But Sen. Charles Schumer (D-NY) says Thune's amendment "has the potential to increase gun violence in communities, put more police officers at risk and nullify state gun laws."

Take that, Harry Reid.