Sen. Bayh may have a lot riding on Pa.

Sen. Evan Bayh does not appear on Tuesday’s Pennsylvania presidential primary ballot, but the Indiana Democrat’s political future and his state’s role in choosing the Democratic nominee are directly tied to the contest.

A comfortable win in Pennsylvania for Sen. Hillary Rodham Clinton (D-N.Y.) keeps the former first lady competitive against Sen. Barack Obama (D-Ill.) and increases the importance of Indiana’s May 6 primary.

{mosads}It also helps Bayh, a former two-term governor and son of U.S. Sen. Birch Bayh who has been mentioned as a possible Clinton running mate. He’s been busy traveling his home turf with the New York senator, helping her chip away at Obama’s lead.

Should Clinton win Pennsylvania by only a few percentage points, or on the off chance lose, the Hoosier State — and Bayh — could see a big opportunity slip away.

“We’re excited about mattering,” he said in an interview with The Hill in his Senate office. “People have been coming to our state to raise money, or more often just to fly over, for years. So we’re kind of happy to have our say. We don’t like being ignored.”

Indiana voters could have a hand in deciding the Democratic presidential candidate for the first time in four decades, going back to the 1968 race between Bobby Kennedy and Eugene McCarthy.

Bayh and Clinton have 20 years of history, and his support for the former first lady has been pivotal in the Midwest. Bayh and former President Bill Clinton are friends and fellow former governors. Last September Bayh was among the first senators to endorse Hillary Clinton for president.

The two senators sit next to each other on the Senate’s Armed Services Committee and have bonded during trips to Iraq, Pakistan and Afghanistan.

This year, Bayh’s support for Clinton has run deep, including lining up a network of backers that includes many of the state’s mayors and state legislators, former Gov. Joe Kernan and Judy O’Bannon, the wife of late Gov. Frank O’Bannon. Bayh’s network is particularly powerful because his gubernatorial history was relatively recent and he maintained high approval ratings throughout his time in the governor’s office from 1989 to 1997 — particularly for a Democrat in a conservative state.

That network is being tested, however, by Obama’s popularity in neighboring Illinois and the money he is spending freely on advertising. Nearly a fifth of Indiana households get Chicago TV stations because they are in the state’s industrial, population-dense northwest corner near the Windy City.

Those East Chicago-Gary-area neighborhoods are also the state’s biggest Democratic base, along with Indianapolis, and Obama’s appeal runs deep there even though Clinton was born and raised in Chicago.

Indiana Democratic Party Chairman Dan Parker, who has endorsed Clinton, predicts the Hoosier State will stay in play even after Pennsylvania voters weigh in. Like Bayh, he cedes a slight edge to Obama but says Clinton’s appeal runs deep.

“Based on the amount of activity going on here by both campaigns, I would say this is probably the last battleground state,” Parker said. “If you take the polls at face value, it’s a dead heat here.

Obviously the Pennsylvania results are important in the larger scheme, but the messages that have been made here will resonate more than who won somewhere else.”

The verdict of Indiana voters could also matter more than in North Carolina since Clinton is already expected to lose that state’s primary to Obama on the same day, said Eric Waltenburg, an associate professor of political science at Purdue University. Waltenburg said Bayh’s chances for the vice presidency would then be either greatly enhanced or all but dismissed.

“Should she pull out of the fire, there’s a good chance he would be talked about,” Waltenburg said. “He has the benefit of being from a state that under ordinary circumstances the Democrats would have no hope of winning. But put Bayh on the ticket, and it does become contested. It’s all an upside for him.”

Bayh has earned a reputation as a centrist, including a close and effective relationship with Indiana colleague Sen. Richard Lugar (R), with whom he shares an interest in foreign policy.

That reputation has been punctuated by occasional leftward moves such as several 2006 votes against Bush administration nominees such as Supreme Court Justices Samuel Alito and John Roberts.

He also raised eyebrows in the Senate in March by being the only Democrat to vote against the Democratic-written federal budget. The 51-44 total meant Bayh wasn’t needed as a swing vote, but that could change as appropriation season moves along and Clinton and Obama stay out on the campaign trail, endangering the Senate’s fragile 51-49 Democratic majority.

Although criticized for the vote by fellow Senate Democrats, Bayh’s fiscal conservatism dates back to his days as Indiana governor and could help Clinton in a general election. He pushed through the largest tax cut in state history and once vetoed a budget passed by Democratic legislators, for example — one reason he left office in 1997 with approval ratings in the high 70s.

Bayh said the budget seemed aimed more at raising revenue than at being fiscally responsible. Past budgets came in times of a healthier economy, he noted, while the current downturn means the government should be cutting back.

“I was able to do a lot of progressive things as governor, but it was always done on a foundation of fiscal responsibility and keeping an eye on spending,” he said. “My principal objection is that I don’t see that happening here.”

Besides Clinton, Bayh is close to Sen. Tom Carper (D-Del.), also a former governor and member of the Senate’s Banking and Aging committees with Bayh.

“I like to call him ‘a recovering governor’ like me,” Carper said. “He’s from a state with a lot of Republican voters, and the way he was effective is that he governed from the middle. He still does that today.”