The outcome of the Democratic presidential primary, which may be decided by Tuesday’s contests in Texas and Ohio, could significantly boost Sen. Dick Durbin’s (D-Ill.) stock in the upper chamber.

Durbin, the second-ranking Democrat in the Senate, has been an outspoken supporter and one of Sen. Barack Obama’s (D-Ill.) most trusted advisers since the Democratic presidential front-runner ran for Congress in 2004.

Durbin and Schumer are housemates and friends, but they are also rivals, say Senate insiders.

Both men are ambitious and are considered the two most obvious candidates to become majority leader when Reid steps down from the post, although Reid has no plans to leave the Senate anytime soon.

Several Senate aides and Democratic lobbyists speculate that Sen. Hillary Rodham Clinton (D-N.Y.) may also be interested in the Senate’s highest leadership post if she fails to win the party nomination.

Yet the chances of such a bid appear unlikely.

Even though Durbin ranks right behind Reid, Schumer has attracted more headlines over the last couple of years for his fundraising prowess and campaign strategies that catapulted Democrats to majority status. Schumer is also a frequent guest on talk shows and well -known for attracting publicity, more so than Durbin.

Obama as president would give Durbin a crucial edge in a future leadership contest. Even as the party’s standard-bearer, Obama would increase Durbin’s stature in Democratic political circles, which have been long dominated by Clinton administration veterans.   

“If there was to be a change, that if there’s a choice to be made and the nominee or the president [is Obama], I think it will be an advantage,” said Sen. Frank Lautenberg (D-N.J.), discussing how Obama’s rise in the party would help Durbin’s standing in a possible leadership showdown.

But Lautenberg said he did not expect Reid to step aside and said that Schumer’s support for Clinton would not hurt his standing.

“Each one is respected for his work and the effort they put in promoting Democratic ideals,” said Lautenberg. “They have won their stripes already and they’re not going to get demoted.”

Schumer, an ardent supporter of Clinton, has worked with the junior senator on many projects affecting New York. He would also stand to benefit from the outcome of the presidential election should she mount a political comeback.

Schumer has taken a visible role in Clinton’s battle with Obama over superdelegates. He declared recently that superdelegates are not obligated to vote the same way as most pledged delegates, a position that helps Clinton, who trails Obama in the delegate count.

Durbin, for his part, put pressure on Clinton over the weekend to consider dropping out of the race.

“I hope that her decision on her future after Tuesday is made in the interest of unity of our party and ultimately winning in November,” he said on Fox News Sunday.