On a vote of 68-31, the U.S. Senate moved to start formal debate on a Democratic gun control bill, as 16 Republicans joined with all but two Democrats to begin floor action on gun control.

"The hard work is starting now," said Senate Majority Leader Harry Reid, after Democrats had moved over the first of what could be many hurdles to this gun legislation.

The vote shut off a Republican filibuster on what is known as the "Motion to Proceed" to the gun bill; another Republican filibuster is still a possibility when the bill actually gets to the Senate floor.

Here are the 16 Republican Senators who voted to begin debate on guns:

Alexander (TN), Ayotte (NH), Burr (NC), Chambliss (GA), Coburn (OK), Collins (ME), Corker (TN), Flake (AZ), Graham (SC), Heller (NV), Hoeven (ND), Isakson (GA), Kirk (IL), McCain (AZ), Toomey (PA) and Wicker (MS).

The two Democrats who voted for the filibuster against the gun bill were Begich of Alaska and Pryor of Arkansas.

As for what is in the bill, this is the "Table of Contents" of the bill as introduced in late March by Democrats in the Senate:

TITLE I—FIX GUN CHECKS ACT

Sec. 101. Short title.

Subtitle A — Ensuring That All Individuals Who Should Be Prohibited From Buying a Gun Are Listed in the National Instant Criminal Background Check System

Sec. 111. Reauthorization of NICS Act Record Improvement Program grants.
Sec. 112. Penalties for States that do not make data electronically available to the National Instant Criminal Background Check System.
Sec. 113. Clarification that Federal court information is to be made available to the National Instant Criminal Background Check System.

Subtitle B — Requiring a Background Check for Every Firearm Sale

Sec. 121. Purpose.
Sec. 122. Firearms transfers.
Sec. 123. Lost and stolen reporting.
Sec. 124. Effective date.

TITLE II—STOP ILLEGAL TRAFFICKING IN FIREARMS ACT

Sec. 201. Short title.
Sec. 202. Hadiya Pendleton and Nyasia Pryear-Yard anti-straw purchasing and firearms trafficking amendments.
Sec. 203. Amendments to section 922(d).
Sec. 204. Amendments to section 924(a).
Sec. 205. Amendments to section 924(h).
Sec. 206. Amendments to section 924(k).
Sec. 207. Limitation on operations by the Department of Justice.

TITLE III—SCHOOL AND CAMPUS SAFETY ENHANCEMENTS ACT

Sec. 301. Short title.
Sec. 302. Grant program for school security.
Sec. 303. Applications.
Sec. 304. Authorization of appropriations.
Sec. 305. Accountability.
Sec. 306. CAMPUS Safety Act of 2013.

The original text of this bill can be found here.

Democrats could still alter the text of the bill before it gets to the floor of the Senate - and we are still waiting to see the exact text of the Manchin/Toomey plan on expanded background checks for gun sales.

As of Thursday morning, no amendments had been filed by any Senators to this bill; that certainly seems like it would change in coming days.

As for the schedule, remember one thing: this is the Senate.

What I mean by that is we could have a very slow legislative process or one that will run in fits and starts.

It is not out of the question to say that debate on this bill could stretch for several weeks.

This first procedural vote was just on the "Motion to Proceed" to the bill; once the bill is officially brought before the Senate, then amendments and extended debate can begin.