His cautious approach to a top Biden priority reflects the divide among Senate Republicans over whether to collaborate with Democrats on part of the president’s spending plans while fighting tooth and nail on the rest. Many Democrats predict McConnell will kill the agreement after stringing talks out for weeks, but the current infrastructure talks are particularly sensitive for the GOP leader because one of his close allies, Ohio Sen. Rob Portman, is the senior Republican negotiator. McConnell is aware of the conventional wisdom that he will ultimately knife the deal and is taking pains not to become the face of its opposition... Sen. Jon Tester (D-Mont.), who helped negotiate the bipartisan framework, was skeptical that McConnell would sink it, given that Democrats could simply then fold the failed cross-aisle deal into their larger partisan package. “I don’t think it would be smart for him to do that, so I don’t think he will,” Tester said. “It’s better for them to pass the bipartisan bill and let the Democrats fight it out on the $3.5 trillion bill.”