The Connecticut Senate race may turn out to be more interesting than expected in the fall. But for today’s primary contests, all of the excitement is in the 5th district.

This seat’s Democratic primary has pitted EMILY’s List, base liberals and President Bill Clinton against each other, and the outcome is not clear. There is similar uncertainty in the GOP race. Both have become increasingly nasty as the summer progressed. The fall outcome could ride on whom the parties nominate.

As for that Senate race, former WWE CEO Linda McMahon is expected to handily defeat former Rep. Christopher Shays in the state’s Senate GOP primary. Likewise, Rep. Christopher Murphy is expected to coast to the nomination on the Democratic side.

Connecticut’s 5th District

The Democratic primary to replace Rep. Christopher Murphy (D), who is running for Senate, has been one of the wildest races of the cycle.

The early frontrunner, state Speaker Chris Donovan, was coasting to the nomination until his campaign went into turmoil in June when two staffers were indicted for alleged campaign finance violations. Donovan has continually denied any knowledge of the matter.

That development gave his two competitors an opening. Former state Rep. Elizabeth Esty seemed at first to benefit the most. She has an organized campaign and the backing of EMILY’s List. That rivalry has set off a proxy fight between EMILY’s List and liberals who are doubling down on Donovan.

Meanwhile, political newcomer Dan Roberti had a low profile for most of the campaign. But in recent weeks, super PAC money has come to his aid through television ads, and he has aired negative spots against Esty and Donovan. On Monday, Roberti was endorsed by President Bill Clinton.

It is hard to tell who has the edge in this race.

The Republican primary has unfolded similarly.

Democrats are most afraid of state Sen. Andrew Roraback. He is a moderate and well-liked. It is for that reason he is perceived as the most dangerous Republican candidate in the context of ethics dominating the Democratic Party’s primary.

But the Republican primary has had ethical issues surface as well.  Businesswoman Lisa Wilson-Foley’s self-funded effort has come under scrutiny, and Democrats are hopeful that she will win the Republican primary. Businessman Mark Greenberg and 2010 candidate Justin Bernier are also in the hunt for the GOP nod.

Much rides on which nominees emerge from both parties. With ethics issues hanging over Donovan and Wilson-Foley, certain matchups will strongly influence each party’s chances in the fall.

Connecticut Senate

Most Connecticut politicos have long declared Rep. Christopher Murphy as the frontrunner over former Connecticut Secretary of State Susan Bysiewicz.

With the exception of EMILY’s List, most of the national Democratic establishment has made it known that Murphy is its preferred candidate. Some on the ground say  Bysiewicz has a record of getting out the vote and should not be underestimated. But on primary day, this is Murphy’s race to lose.

In the Republican primary, former WWE CEO Linda McMahon is making her second run for Senate and former Rep. Christopher Shays is attempting his political comeback.

It has been a bitter fight that McMahon is expected to win. She picked up the state party’s endorsement in May. Shays has fought hard, but he has not been able to keep up with McMahon’s self-funded financial effort.

National Republicans wrote off this seat last fall, but they have recently changed their posture, praising McMahon’s campaign execution.