A bigger majority means more Democratic defectors

At least three dozen vulnerable Democrats have deserted their party during important votes this year — a move that could bolster their reelection chances but has left Democrats lacking unity.

The tougher their districts, the more often vulnerable Democrats have sided with Republicans, according to The Hill’s analysis of 15 major votes cast in the first six months of the 111th Congress. The analysis included major bills and votes in which at least 10 Democrats voted against their party.

The 50-plus Democrats considered vulnerable by The Cook Political Report have voted with Republicans about 20 percent of the time on those 15 votes. Some of the members didn’t desert the party on any of the major votes.

The votes include last week’s climate change bill, the stimulus package, President Obama’s budget and other votes like an amendment to cut off funding for the closure of Guantánamo Bay prison.

The defection rate has been much higher in the subset of 10 Democrats whose districts went for GOP presidential nominee John McCainJohn Sidney McCainDon’t disrespect McCain by torpedoing his clean National Defense Authorization Act Meghan McCain rips Trump's 'gross' line about her dad Trump's America fights back MORE (R-Ariz.) by double digits — 45 percent. All but one voted with Republicans on the energy bill and all but two voted to keep Guantánamo open.

But there are exceptions to the rule.

Rep. Chet Edwards (Texas), whose district went for McCain by more than any other Democrat — 67-32 — has largely stuck with his party. His vote against the energy bill was only his second in the 15 votes. That allows Republicans aiming for his seat to peg him with his support for the stimulus, the budget and myriad other Democratic positions.

On the other end of the spectrum, Rep. Joe DonnellyJoseph (Joe) Simon DonnellyElection Countdown: Family separation policy may haunt GOP in November | Why Republican candidates are bracing for surprises | House Dems rake in record May haul | 'Dumpster fire' ad goes viral Actress Marcia Gay Harden urges Congress to boost Alzheimer's funding Manchin becomes final Democrat to back bill preventing separation of immigrant families MORE’s (Ind.) district went for Obama by 9 percent, yet he has deserted his party on a majority of the 15 votes. Donnelly is not considered the biggest target on the map, yet his votes are on a par with those of Rep. Travis Childers (D-Miss.), whose district went for McCain by 25 points.

Other interesting examples include Reps. Zack Space (Ohio), Mike McMahon (N.Y.), John Murtha (Pa.) and Charlie Melancon (La.).

Despite representing districts that went for McCain in 2008, neither Space, McMahon nor Murtha has joined Republicans on any of the 15 votes.

Melancon, meanwhile, is primed to enter his state’s Senate race, and whether he ran statewide (McCain won Louisiana by 19 percent) or just for his House seat (McCain won the district by 24 percent), he would be dealing with a heavily McCain voter bloc.

Still, Melancon has largely stuck by his party, with his climate change vote just the fourth of the 15 on which he has joined Republicans. Melancon has missed two of the votes, but his votes in favor of the stimulus and the budget are already points of emphasis for the GOP in his probable campaign against Sen. David VitterDavid Bruce VitterSenate panel advances Trump nominee who wouldn't say if Brown v. Board of Education was decided correctly Planned Parenthood targets judicial nominee over abortion comments Trump nominates wife of ex-Louisiana senator to be federal judge MORE (R-La.).

Melancon’s four defections pale in comparison to others, including Idaho’s Walt Minnick (10 defections), Alabama’s Bobby Bright (13) and several others who clocked in with eight defections.

Bright registered the most defections, leaving his party on every vote except the omnibus bill in February and the recent war supplemental. On the latter bill, most defectors came from the liberal wing of the party, even though other vulnerable Democrats like Reps. Eric Massa (N.Y.), Alan GraysonAlan Mark GraysonThe Hill's Morning Report: Frustration mounts as Republicans blow up tax message Former Dem Rep. Alan Grayson to challenge for old House seat PolitiFact cancels Alan Grayson hire after backlash MORE (Fla.) and Carol Shea-Porter (N.H.) joined them.

Not all votes are created equal. Republicans are particularly focused on going after Democrats for their votes on the energy bill, the stimulus and Obama’s budget. They have already run ads on all three issues and will continue to hammer away as the cycle goes on.

Paul Lindsay, a spokesman for the National Republican Congressional Committee, said Democrats who voted with their party on those three issues “should expect an uphill battle between now and Election Day.”

“It’s hard to hide as a so-called ‘centrist’ Democrat when you are blatantly backing Nancy Pelosi’s partisan agenda that is expanding the size of government and doing nothing to create jobs,” Lindsay said.

Ryan Rudominer, a spokesman for the Democratic Congressional Campaign Committee, said the dissent among vulnerable Democrats shows how welcoming the party is of other viewpoints.

“Our Democratic Frontline members are independent voices who put the families of their districts first,” Rudominer said. “Unlike the Republicans, the Democrats have a big tent where a diversity of viewpoints is welcomed.”

To see a chart, please click here.