The 2014 election battle for control of the Senate will affect just about everything it does this year and next, because it could take just a handful of upsets to put the Republicans back in charge.
The two-year, midterm election cycle, which is off to a faster pace than usual in the Senate, certainly affected the gun control vote when five Democrats from conservative-leaning states voted against it.
Two of the Democrats' no votes were Sens. Mark Pryor of Arkansas and Mark Begich of Alaska who will face the voters next year in states where gun control isn't popular. The upcoming votes on immigration reform will also pose a tough test for Democrats in states where the issue is just as unpopular.
Democrats control 55 seats in the Senate, including two Independents who usually vote with them. But once again, the Republicans have a stronger numerical advantage in next year's Senate races, because 21 Democratic seats are at stake compared to just 14 for the Republicans.
Making matters even tougher for Democrats, six of their seats will be open races due to retirements. The GOP has a better than even chance of picking up four of them: Iowa (Tom Harkin), Montana (Max Baucus), South Dakota (Tim Johnson) and West Virginia (John D. Rockefeller).
The Cook Political Report, which closely tracks House and Senate races, calls all four contests pure "toss ups."
The widely-followed Rothenberg Political Report rates the West Virginia race somewhere between a toss-up to "Tilt Republican."
At this writing, only two Senate Republicans are retiring: Sen. Saxby Chambliss of Georgia and Mike Johanns of Nebraska. Both seats are considered safe for the GOP.
In fact, Cook says all 14 Republican seats up next year are either "likely" to remain in GOP hands or "solid" slam dunks for the party.
If the GOP were to win all the toss-up races, they would need just two more seats to control the Senate, which may not be likely at this point but it's not impossible, according to election handicappers.
Notably, Cook puts these six Democratic seats in the shakier "lean Democratic" column: Sens. Mark Begich, Alaska; Mark Pryor, Arkansas; Mary Landrieu, Louisiana; Al Franken, Minnesota; Kay Hagan, North Carolina; and retiring Sen. Carl Levin of Michigan.
Depending upon their Republican opponents -- and it's too early to assess that lineup -- the GOP has a chance to take over the Senate with the right candidates.
And with the right issues -- which, as of now, appear to be rapidly trending against the Democrats on a number of fronts.