Although the noise of the presidential race is loud and sustained, expect a higher volume soon in Pa.'s U.S. Senate race.

That's because the money pouring into Pennsylvania from outside groups and special interests is now tops in the U.S.A., according to the non-profit watchdog Center for Responsive Politics.

The Pittsburgh Tribune-Review reports the closely-contested Pat Toomey-Katie McGinty battle has so far collected at least $57.5 million in outside dough. And The Washington Post says more is on the way.

The level of incoming money surpasses all other Senate contests and serves as evidence that the Keystone State remains a key to Democratic hopes of winning Senate control.

Perhaps ironically, McGinty supports overthrowing Citizens United, the Supreme Court ruling that opened the gates for unlimited campaign funding, yet is benefiting more from the ruling than Toomey, who supports the Citizens United decision on the basis of free speech.

The Trib-Review says McGinty got $38.9 million in support from outside liberal groups while Toomey got $18.6 million from conservative groups.

You can read the Trib's report right here.

Spending by candidates' campaigns, however, is very different: Toomey's campaign spent $15.4 million through the end of June; McGinty's spent $4.3 million. The next required campaign finance filing date is Oct. 15.

So at this stage more money ($42.2 million) is invested in electing McGinty than in electing Toomey ($34 million). But as we enter the last month of the campaign, it's clear there's more to come.

The Washington Post reports the GOP Senate PAC is plowing millions (as in $21 million more) into six Senate races, including Pennsylvania's, as part of efforts to retain Senate control.

The Post says that means a total of $76 million from the Senate Leadership Fund for the last two months of the cycle, an amount the newspaper says could grow larger by Election Day.

You can read The Post report right here.

The McGinty/Toomey race is tight and will clearly end up costing more than $80 million. There are two debates scheduled. The first is in Pittsburgh Oct. 17; the second is in Philly Oct. 24.